| Message ID | 20220701162726.31346-2-jim2101024@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | PCI: brcmstb: Re-submit reverted patchset | expand |
On Fri, Jul 01, 2022 at 12:27:22PM -0400, Jim Quinlan wrote: > We need to take some code in brcm_pcie_setup() and put it in a new function > brcm_pcie_linkup(). In future commits the brcm_pcie_linkup() function will > be called indirectly by pci_host_probe() as opposed to the host driver > invoking it directly. > > Some code that was executed after the PCIe linkup is now placed so that it > executes prior to linkup, since this code has to run prior to the > invocation of pci_host_probe(). This says we need to move some code from brcm_pcie_setup() to brcm_pcie_linkup(), but not *why* we need to do that. In brcm_pcie_resume(), they're called together: brcm_pcie_resume brcm_pcie_setup brcm_pcie_linkup In the probe path, they're not called together, but they're in the same order: brcm_pcie_probe brcm_pcie_setup pci_host_probe ... brcm_pcie_add_bus # bus->ops->add_bus brcm_pcie_linkup Is there something that must happen *between* them in the probe path? > Link: https://lore.kernel.org/r/20220106160332.2143-5-jim2101024@gmail.com > Signed-off-by: Jim Quinlan <jim2101024@gmail.com> > --- > drivers/pci/controller/pcie-brcmstb.c | 69 +++++++++++++++++---------- > 1 file changed, 43 insertions(+), 26 deletions(-) > > diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c > index e61058e13818..2bf5cc399fd0 100644 > --- a/drivers/pci/controller/pcie-brcmstb.c > +++ b/drivers/pci/controller/pcie-brcmstb.c > @@ -926,16 +926,9 @@ static inline int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie, > > static int brcm_pcie_setup(struct brcm_pcie *pcie) > { > - struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie); > u64 rc_bar2_offset, rc_bar2_size; > void __iomem *base = pcie->base; > - struct device *dev = pcie->dev; > - struct resource_entry *entry; > - bool ssc_good = false; > - struct resource *res; > - int num_out_wins = 0; > - u16 nlw, cls, lnksta; > - int i, ret, memc; > + int ret, memc; > u32 tmp, burst, aspm_support; > > /* Reset the bridge */ > @@ -1025,6 +1018,40 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) > if (pcie->gen) > brcm_pcie_set_gen(pcie, pcie->gen); > > + /* Don't advertise L0s capability if 'aspm-no-l0s' */ > + aspm_support = PCIE_LINK_STATE_L1; > + if (!of_property_read_bool(pcie->np, "aspm-no-l0s")) > + aspm_support |= PCIE_LINK_STATE_L0S; > + tmp = readl(base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); > + u32p_replace_bits(&tmp, aspm_support, > + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK); > + writel(tmp, base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); > + > + /* > + * For config space accesses on the RC, show the right class for > + * a PCIe-PCIe bridge (the default setting is to be EP mode). > + */ > + tmp = readl(base + PCIE_RC_CFG_PRIV1_ID_VAL3); > + u32p_replace_bits(&tmp, 0x060400, > + PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK); > + writel(tmp, base + PCIE_RC_CFG_PRIV1_ID_VAL3); > + > + return 0; > +} > + > +static int brcm_pcie_linkup(struct brcm_pcie *pcie) > +{ > + struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie); > + struct device *dev = pcie->dev; > + void __iomem *base = pcie->base; > + struct resource_entry *entry; > + struct resource *res; > + int num_out_wins = 0; > + u16 nlw, cls, lnksta; > + bool ssc_good = false; > + u32 tmp; > + int ret, i; > + > /* Unassert the fundamental reset */ > pcie->perst_set(pcie, 0); > > @@ -1075,24 +1102,6 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) > num_out_wins++; > } > > - /* Don't advertise L0s capability if 'aspm-no-l0s' */ > - aspm_support = PCIE_LINK_STATE_L1; > - if (!of_property_read_bool(pcie->np, "aspm-no-l0s")) > - aspm_support |= PCIE_LINK_STATE_L0S; > - tmp = readl(base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); > - u32p_replace_bits(&tmp, aspm_support, > - PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK); > - writel(tmp, base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); > - > - /* > - * For config space accesses on the RC, show the right class for > - * a PCIe-PCIe bridge (the default setting is to be EP mode). > - */ > - tmp = readl(base + PCIE_RC_CFG_PRIV1_ID_VAL3); > - u32p_replace_bits(&tmp, 0x060400, > - PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK); > - writel(tmp, base + PCIE_RC_CFG_PRIV1_ID_VAL3); > - > if (pcie->ssc) { > ret = brcm_pcie_set_ssc(pcie); > if (ret == 0) > @@ -1281,6 +1290,10 @@ static int brcm_pcie_resume(struct device *dev) > if (ret) > goto err_reset; > > + ret = brcm_pcie_linkup(pcie); > + if (ret) > + goto err_reset; > + > if (pcie->msi) > brcm_msi_set_regs(pcie->msi); > > @@ -1398,6 +1411,10 @@ static int brcm_pcie_probe(struct platform_device *pdev) > if (ret) > goto fail; > > + ret = brcm_pcie_linkup(pcie); > + if (ret) > + goto fail; > + > pcie->hw_rev = readl(pcie->base + PCIE_MISC_REVISION); > if (pcie->type == BCM4908 && pcie->hw_rev >= BRCM_PCIE_HW_REV_3_20) { > dev_err(pcie->dev, "hardware revision with unsupported PERST# setup\n"); > -- > 2.17.1 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Wed, Jul 6, 2022 at 5:56 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > On Fri, Jul 01, 2022 at 12:27:22PM -0400, Jim Quinlan wrote: > > We need to take some code in brcm_pcie_setup() and put it in a new function > > brcm_pcie_linkup(). In future commits the brcm_pcie_linkup() function will > > be called indirectly by pci_host_probe() as opposed to the host driver > > invoking it directly. > > > > Some code that was executed after the PCIe linkup is now placed so that it > > executes prior to linkup, since this code has to run prior to the > > invocation of pci_host_probe(). > > This says we need to move some code from brcm_pcie_setup() to > brcm_pcie_linkup(), but not *why* we need to do that. I will elaborate in the commit message. > > In brcm_pcie_resume(), they're called together: > > brcm_pcie_resume > brcm_pcie_setup > brcm_pcie_linkup > > In the probe path, they're not called together, but they're in the > same order: > > brcm_pcie_probe > brcm_pcie_setup > pci_host_probe > ... > brcm_pcie_add_bus # bus->ops->add_bus > brcm_pcie_linkup > > Is there something that must happen *between* them in the probe path? Yes. In the probe() case, we must do things in this order: 1. brcm_pcie_setup() 2. Turn on regulators 3. brcm_pcie_linkup() Since the voltage regulators are turned on during enumeration, pci_host_probe() must be invoked prior to 3. Before regulators, we did not care. In the resume case, there is no enumeration of course but our driver has a handle to the regulators and can turn them on/off w/o help. Regards, Jim Quinlan Broradcom STB > > > Link: https://lore.kernel.org/r/20220106160332.2143-5-jim2101024@gmail.com > > Signed-off-by: Jim Quinlan <jim2101024@gmail.com> > > --- > > drivers/pci/controller/pcie-brcmstb.c | 69 +++++++++++++++++---------- > > 1 file changed, 43 insertions(+), 26 deletions(-) > > > > diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c > > index e61058e13818..2bf5cc399fd0 100644 > > --- a/drivers/pci/controller/pcie-brcmstb.c > > +++ b/drivers/pci/controller/pcie-brcmstb.c > > @@ -926,16 +926,9 @@ static inline int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie, > > > > static int brcm_pcie_setup(struct brcm_pcie *pcie) > > { > > - struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie); > > u64 rc_bar2_offset, rc_bar2_size; > > void __iomem *base = pcie->base; > > - struct device *dev = pcie->dev; > > - struct resource_entry *entry; > > - bool ssc_good = false; > > - struct resource *res; > > - int num_out_wins = 0; > > - u16 nlw, cls, lnksta; > > - int i, ret, memc; > > + int ret, memc; > > u32 tmp, burst, aspm_support; > > > > /* Reset the bridge */ > > @@ -1025,6 +1018,40 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) > > if (pcie->gen) > > brcm_pcie_set_gen(pcie, pcie->gen); > > > > + /* Don't advertise L0s capability if 'aspm-no-l0s' */ > > + aspm_support = PCIE_LINK_STATE_L1; > > + if (!of_property_read_bool(pcie->np, "aspm-no-l0s")) > > + aspm_support |= PCIE_LINK_STATE_L0S; > > + tmp = readl(base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); > > + u32p_replace_bits(&tmp, aspm_support, > > + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK); > > + writel(tmp, base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); > > + > > + /* > > + * For config space accesses on the RC, show the right class for > > + * a PCIe-PCIe bridge (the default setting is to be EP mode). > > + */ > > + tmp = readl(base + PCIE_RC_CFG_PRIV1_ID_VAL3); > > + u32p_replace_bits(&tmp, 0x060400, > > + PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK); > > + writel(tmp, base + PCIE_RC_CFG_PRIV1_ID_VAL3); > > + > > + return 0; > > +} > > + > > +static int brcm_pcie_linkup(struct brcm_pcie *pcie) > > +{ > > + struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie); > > + struct device *dev = pcie->dev; > > + void __iomem *base = pcie->base; > > + struct resource_entry *entry; > > + struct resource *res; > > + int num_out_wins = 0; > > + u16 nlw, cls, lnksta; > > + bool ssc_good = false; > > + u32 tmp; > > + int ret, i; > > + > > /* Unassert the fundamental reset */ > > pcie->perst_set(pcie, 0); > > > > @@ -1075,24 +1102,6 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) > > num_out_wins++; > > } > > > > - /* Don't advertise L0s capability if 'aspm-no-l0s' */ > > - aspm_support = PCIE_LINK_STATE_L1; > > - if (!of_property_read_bool(pcie->np, "aspm-no-l0s")) > > - aspm_support |= PCIE_LINK_STATE_L0S; > > - tmp = readl(base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); > > - u32p_replace_bits(&tmp, aspm_support, > > - PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK); > > - writel(tmp, base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); > > - > > - /* > > - * For config space accesses on the RC, show the right class for > > - * a PCIe-PCIe bridge (the default setting is to be EP mode). > > - */ > > - tmp = readl(base + PCIE_RC_CFG_PRIV1_ID_VAL3); > > - u32p_replace_bits(&tmp, 0x060400, > > - PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK); > > - writel(tmp, base + PCIE_RC_CFG_PRIV1_ID_VAL3); > > - > > if (pcie->ssc) { > > ret = brcm_pcie_set_ssc(pcie); > > if (ret == 0) > > @@ -1281,6 +1290,10 @@ static int brcm_pcie_resume(struct device *dev) > > if (ret) > > goto err_reset; > > > > + ret = brcm_pcie_linkup(pcie); > > + if (ret) > > + goto err_reset; > > + > > if (pcie->msi) > > brcm_msi_set_regs(pcie->msi); > > > > @@ -1398,6 +1411,10 @@ static int brcm_pcie_probe(struct platform_device *pdev) > > if (ret) > > goto fail; > > > > + ret = brcm_pcie_linkup(pcie); > > + if (ret) > > + goto fail; > > + > > pcie->hw_rev = readl(pcie->base + PCIE_MISC_REVISION); > > if (pcie->type == BCM4908 && pcie->hw_rev >= BRCM_PCIE_HW_REV_3_20) { > > dev_err(pcie->dev, "hardware revision with unsupported PERST# setup\n"); > > -- > > 2.17.1 > > > > > > _______________________________________________ > > linux-arm-kernel mailing list > > linux-arm-kernel@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Fri, Jul 08, 2022 at 09:29:27AM -0400, Jim Quinlan wrote: > On Wed, Jul 6, 2022 at 5:56 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > On Fri, Jul 01, 2022 at 12:27:22PM -0400, Jim Quinlan wrote: > > > We need to take some code in brcm_pcie_setup() and put it in a new function > > > brcm_pcie_linkup(). In future commits the brcm_pcie_linkup() function will > > > be called indirectly by pci_host_probe() as opposed to the host driver > > > invoking it directly. > > > > > > Some code that was executed after the PCIe linkup is now placed so that it > > > executes prior to linkup, since this code has to run prior to the > > > invocation of pci_host_probe(). > > > > This says we need to move some code from brcm_pcie_setup() to > > brcm_pcie_linkup(), but not *why* we need to do that. > I will elaborate in the commit message. > > > > In brcm_pcie_resume(), they're called together: > > > > brcm_pcie_resume > > brcm_pcie_setup > > brcm_pcie_linkup > > > > In the probe path, they're not called together, but they're in the > > same order: > > > > brcm_pcie_probe > > brcm_pcie_setup > > pci_host_probe > > ... > > brcm_pcie_add_bus # bus->ops->add_bus > > brcm_pcie_linkup > > > > Is there something that must happen *between* them in the probe path? > > Yes. In the probe() case, we must do things in this order: > > 1. brcm_pcie_setup() > 2. Turn on regulators > 3. brcm_pcie_linkup() Ah, I see, both 2) and 3) happen in brcm_pcie_add_bus: brcm_pcie_add_bus # bus->ops->add_bus pci_subdev_regulators_add_bus regulator_bulk_enable # turn on regulators brcm_pcie_linkup > Since the voltage regulators are turned on during enumeration, > pci_host_probe() must be invoked prior to 3. Before regulators, we > did not care. I guess in the pre-regulator case, i.e., pcie->sr not set, the power for downstream devices must always be on. > In the resume case, there is no enumeration of course but our driver > has a handle to the regulators and can turn them on/off w/o help. And I guess we don't need brcm_pcie_setup() in the resume path because suspend turns off power only for downstream devices, not for the root port itself, so the programming done by brcm_pcie_setup() doesn't need to be done again. > > > Link: https://lore.kernel.org/r/20220106160332.2143-5-jim2101024@gmail.com > > > Signed-off-by: Jim Quinlan <jim2101024@gmail.com> > > > --- > > > drivers/pci/controller/pcie-brcmstb.c | 69 +++++++++++++++++---------- > > > 1 file changed, 43 insertions(+), 26 deletions(-) > > > > > > diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c > > > index e61058e13818..2bf5cc399fd0 100644 > > > --- a/drivers/pci/controller/pcie-brcmstb.c > > > +++ b/drivers/pci/controller/pcie-brcmstb.c > > > @@ -926,16 +926,9 @@ static inline int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie, > > > > > > static int brcm_pcie_setup(struct brcm_pcie *pcie) > > > { > > > - struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie); > > > u64 rc_bar2_offset, rc_bar2_size; > > > void __iomem *base = pcie->base; > > > - struct device *dev = pcie->dev; > > > - struct resource_entry *entry; > > > - bool ssc_good = false; > > > - struct resource *res; > > > - int num_out_wins = 0; > > > - u16 nlw, cls, lnksta; > > > - int i, ret, memc; > > > + int ret, memc; > > > u32 tmp, burst, aspm_support; > > > > > > /* Reset the bridge */ > > > @@ -1025,6 +1018,40 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) > > > if (pcie->gen) > > > brcm_pcie_set_gen(pcie, pcie->gen); > > > > > > + /* Don't advertise L0s capability if 'aspm-no-l0s' */ > > > + aspm_support = PCIE_LINK_STATE_L1; > > > + if (!of_property_read_bool(pcie->np, "aspm-no-l0s")) > > > + aspm_support |= PCIE_LINK_STATE_L0S; > > > + tmp = readl(base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); > > > + u32p_replace_bits(&tmp, aspm_support, > > > + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK); > > > + writel(tmp, base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); > > > + > > > + /* > > > + * For config space accesses on the RC, show the right class for > > > + * a PCIe-PCIe bridge (the default setting is to be EP mode). > > > + */ > > > + tmp = readl(base + PCIE_RC_CFG_PRIV1_ID_VAL3); > > > + u32p_replace_bits(&tmp, 0x060400, > > > + PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK); > > > + writel(tmp, base + PCIE_RC_CFG_PRIV1_ID_VAL3); > > > + > > > + return 0; > > > +} > > > + > > > +static int brcm_pcie_linkup(struct brcm_pcie *pcie) > > > +{ > > > + struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie); > > > + struct device *dev = pcie->dev; > > > + void __iomem *base = pcie->base; > > > + struct resource_entry *entry; > > > + struct resource *res; > > > + int num_out_wins = 0; > > > + u16 nlw, cls, lnksta; > > > + bool ssc_good = false; > > > + u32 tmp; > > > + int ret, i; > > > + > > > /* Unassert the fundamental reset */ > > > pcie->perst_set(pcie, 0); > > > > > > @@ -1075,24 +1102,6 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) > > > num_out_wins++; > > > } > > > > > > - /* Don't advertise L0s capability if 'aspm-no-l0s' */ > > > - aspm_support = PCIE_LINK_STATE_L1; > > > - if (!of_property_read_bool(pcie->np, "aspm-no-l0s")) > > > - aspm_support |= PCIE_LINK_STATE_L0S; > > > - tmp = readl(base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); > > > - u32p_replace_bits(&tmp, aspm_support, > > > - PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK); > > > - writel(tmp, base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); > > > - > > > - /* > > > - * For config space accesses on the RC, show the right class for > > > - * a PCIe-PCIe bridge (the default setting is to be EP mode). > > > - */ > > > - tmp = readl(base + PCIE_RC_CFG_PRIV1_ID_VAL3); > > > - u32p_replace_bits(&tmp, 0x060400, > > > - PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK); > > > - writel(tmp, base + PCIE_RC_CFG_PRIV1_ID_VAL3); > > > - > > > if (pcie->ssc) { > > > ret = brcm_pcie_set_ssc(pcie); > > > if (ret == 0) > > > @@ -1281,6 +1290,10 @@ static int brcm_pcie_resume(struct device *dev) > > > if (ret) > > > goto err_reset; > > > > > > + ret = brcm_pcie_linkup(pcie); > > > + if (ret) > > > + goto err_reset; > > > + > > > if (pcie->msi) > > > brcm_msi_set_regs(pcie->msi); > > > > > > @@ -1398,6 +1411,10 @@ static int brcm_pcie_probe(struct platform_device *pdev) > > > if (ret) > > > goto fail; > > > > > > + ret = brcm_pcie_linkup(pcie); > > > + if (ret) > > > + goto fail; > > > + > > > pcie->hw_rev = readl(pcie->base + PCIE_MISC_REVISION); > > > if (pcie->type == BCM4908 && pcie->hw_rev >= BRCM_PCIE_HW_REV_3_20) { > > > dev_err(pcie->dev, "hardware revision with unsupported PERST# setup\n"); > > > -- > > > 2.17.1 > > > > > > > > > _______________________________________________ > > > linux-arm-kernel mailing list > > > linux-arm-kernel@lists.infradead.org > > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Fri, Jul 8, 2022 at 3:04 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > On Fri, Jul 08, 2022 at 09:29:27AM -0400, Jim Quinlan wrote: > > On Wed, Jul 6, 2022 at 5:56 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > > On Fri, Jul 01, 2022 at 12:27:22PM -0400, Jim Quinlan wrote: > > > > We need to take some code in brcm_pcie_setup() and put it in a new function > > > > brcm_pcie_linkup(). In future commits the brcm_pcie_linkup() function will > > > > be called indirectly by pci_host_probe() as opposed to the host driver > > > > invoking it directly. > > > > > > > > Some code that was executed after the PCIe linkup is now placed so that it > > > > executes prior to linkup, since this code has to run prior to the > > > > invocation of pci_host_probe(). > > > > > > This says we need to move some code from brcm_pcie_setup() to > > > brcm_pcie_linkup(), but not *why* we need to do that. > > I will elaborate in the commit message. > > > > > > In brcm_pcie_resume(), they're called together: > > > > > > brcm_pcie_resume > > > brcm_pcie_setup > > > brcm_pcie_linkup > > > > > > In the probe path, they're not called together, but they're in the > > > same order: > > > > > > brcm_pcie_probe > > > brcm_pcie_setup > > > pci_host_probe > > > ... > > > brcm_pcie_add_bus # bus->ops->add_bus > > > brcm_pcie_linkup > > > > > > Is there something that must happen *between* them in the probe path? > > > > Yes. In the probe() case, we must do things in this order: > > > > 1. brcm_pcie_setup() > > 2. Turn on regulators > > 3. brcm_pcie_linkup() > > Ah, I see, both 2) and 3) happen in brcm_pcie_add_bus: > > brcm_pcie_add_bus # bus->ops->add_bus > pci_subdev_regulators_add_bus > regulator_bulk_enable # turn on regulators > brcm_pcie_linkup > > > Since the voltage regulators are turned on during enumeration, > > pci_host_probe() must be invoked prior to 3. Before regulators, we > > did not care. > > I guess in the pre-regulator case, i.e., pcie->sr not set, the power > for downstream devices must always be on. > > > In the resume case, there is no enumeration of course but our driver > > has a handle to the regulators and can turn them on/off w/o help. > > And I guess we don't need brcm_pcie_setup() in the resume path because > suspend turns off power only for downstream devices, not for the root > port itself, so the programming done by brcm_pcie_setup() doesn't need > to be done again. I'm not sure I understand what you are saying -- brcm_pcie_setup() is called by brcm_pcie_resume() because it is needed. brcm_pcie_setup() isn't concerned with power it just does the preparation required before attempting link-up. Regards, Jim Quinlan Broadcom STB > > > > > Link: https://lore.kernel.org/r/20220106160332.2143-5-jim2101024@gmail.com > > > > Signed-off-by: Jim Quinlan <jim2101024@gmail.com> > > > > --- > > > > drivers/pci/controller/pcie-brcmstb.c | 69 +++++++++++++++++---------- > > > > 1 file changed, 43 insertions(+), 26 deletions(-) > > > > > > > > diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c > > > > index e61058e13818..2bf5cc399fd0 100644 > > > > --- a/drivers/pci/controller/pcie-brcmstb.c > > > > +++ b/drivers/pci/controller/pcie-brcmstb.c > > > > @@ -926,16 +926,9 @@ static inline int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie, > > > > > > > > static int brcm_pcie_setup(struct brcm_pcie *pcie) > > > > { > > > > - struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie); > > > > u64 rc_bar2_offset, rc_bar2_size; > > > > void __iomem *base = pcie->base; > > > > - struct device *dev = pcie->dev; > > > > - struct resource_entry *entry; > > > > - bool ssc_good = false; > > > > - struct resource *res; > > > > - int num_out_wins = 0; > > > > - u16 nlw, cls, lnksta; > > > > - int i, ret, memc; > > > > + int ret, memc; > > > > u32 tmp, burst, aspm_support; > > > > > > > > /* Reset the bridge */ > > > > @@ -1025,6 +1018,40 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) > > > > if (pcie->gen) > > > > brcm_pcie_set_gen(pcie, pcie->gen); > > > > > > > > + /* Don't advertise L0s capability if 'aspm-no-l0s' */ > > > > + aspm_support = PCIE_LINK_STATE_L1; > > > > + if (!of_property_read_bool(pcie->np, "aspm-no-l0s")) > > > > + aspm_support |= PCIE_LINK_STATE_L0S; > > > > + tmp = readl(base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); > > > > + u32p_replace_bits(&tmp, aspm_support, > > > > + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK); > > > > + writel(tmp, base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); > > > > + > > > > + /* > > > > + * For config space accesses on the RC, show the right class for > > > > + * a PCIe-PCIe bridge (the default setting is to be EP mode). > > > > + */ > > > > + tmp = readl(base + PCIE_RC_CFG_PRIV1_ID_VAL3); > > > > + u32p_replace_bits(&tmp, 0x060400, > > > > + PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK); > > > > + writel(tmp, base + PCIE_RC_CFG_PRIV1_ID_VAL3); > > > > + > > > > + return 0; > > > > +} > > > > + > > > > +static int brcm_pcie_linkup(struct brcm_pcie *pcie) > > > > +{ > > > > + struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie); > > > > + struct device *dev = pcie->dev; > > > > + void __iomem *base = pcie->base; > > > > + struct resource_entry *entry; > > > > + struct resource *res; > > > > + int num_out_wins = 0; > > > > + u16 nlw, cls, lnksta; > > > > + bool ssc_good = false; > > > > + u32 tmp; > > > > + int ret, i; > > > > + > > > > /* Unassert the fundamental reset */ > > > > pcie->perst_set(pcie, 0); > > > > > > > > @@ -1075,24 +1102,6 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) > > > > num_out_wins++; > > > > } > > > > > > > > - /* Don't advertise L0s capability if 'aspm-no-l0s' */ > > > > - aspm_support = PCIE_LINK_STATE_L1; > > > > - if (!of_property_read_bool(pcie->np, "aspm-no-l0s")) > > > > - aspm_support |= PCIE_LINK_STATE_L0S; > > > > - tmp = readl(base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); > > > > - u32p_replace_bits(&tmp, aspm_support, > > > > - PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK); > > > > - writel(tmp, base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); > > > > - > > > > - /* > > > > - * For config space accesses on the RC, show the right class for > > > > - * a PCIe-PCIe bridge (the default setting is to be EP mode). > > > > - */ > > > > - tmp = readl(base + PCIE_RC_CFG_PRIV1_ID_VAL3); > > > > - u32p_replace_bits(&tmp, 0x060400, > > > > - PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK); > > > > - writel(tmp, base + PCIE_RC_CFG_PRIV1_ID_VAL3); > > > > - > > > > if (pcie->ssc) { > > > > ret = brcm_pcie_set_ssc(pcie); > > > > if (ret == 0) > > > > @@ -1281,6 +1290,10 @@ static int brcm_pcie_resume(struct device *dev) > > > > if (ret) > > > > goto err_reset; > > > > > > > > + ret = brcm_pcie_linkup(pcie); > > > > + if (ret) > > > > + goto err_reset; > > > > + > > > > if (pcie->msi) > > > > brcm_msi_set_regs(pcie->msi); > > > > > > > > @@ -1398,6 +1411,10 @@ static int brcm_pcie_probe(struct platform_device *pdev) > > > > if (ret) > > > > goto fail; > > > > > > > > + ret = brcm_pcie_linkup(pcie); > > > > + if (ret) > > > > + goto fail; > > > > + > > > > pcie->hw_rev = readl(pcie->base + PCIE_MISC_REVISION); > > > > if (pcie->type == BCM4908 && pcie->hw_rev >= BRCM_PCIE_HW_REV_3_20) { > > > > dev_err(pcie->dev, "hardware revision with unsupported PERST# setup\n"); > > > > -- > > > > 2.17.1 > > > > > > > > > > > > _______________________________________________ > > > > linux-arm-kernel mailing list > > > > linux-arm-kernel@lists.infradead.org > > > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > > > > > _______________________________________________ > > linux-arm-kernel mailing list > > linux-arm-kernel@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >
On Fri, Jul 08, 2022 at 03:40:43PM -0400, Jim Quinlan wrote: > On Fri, Jul 8, 2022 at 3:04 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > On Fri, Jul 08, 2022 at 09:29:27AM -0400, Jim Quinlan wrote: > > > On Wed, Jul 6, 2022 at 5:56 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > > > On Fri, Jul 01, 2022 at 12:27:22PM -0400, Jim Quinlan wrote: > > > > > We need to take some code in brcm_pcie_setup() and put it in a new function > > > > > brcm_pcie_linkup(). In future commits the brcm_pcie_linkup() function will > > > > > be called indirectly by pci_host_probe() as opposed to the host driver > > > > > invoking it directly. > > > > > > > > > > Some code that was executed after the PCIe linkup is now placed so that it > > > > > executes prior to linkup, since this code has to run prior to the > > > > > invocation of pci_host_probe(). > > > > > > > > This says we need to move some code from brcm_pcie_setup() to > > > > brcm_pcie_linkup(), but not *why* we need to do that. > > > I will elaborate in the commit message. > > > > > > > > In brcm_pcie_resume(), they're called together: > > > > > > > > brcm_pcie_resume > > > > brcm_pcie_setup > > > > brcm_pcie_linkup > > > > > > > > In the probe path, they're not called together, but they're in the > > > > same order: > > > > > > > > brcm_pcie_probe > > > > brcm_pcie_setup > > > > pci_host_probe > > > > ... > > > > brcm_pcie_add_bus # bus->ops->add_bus > > > > brcm_pcie_linkup > > > > > > > > Is there something that must happen *between* them in the probe path? > > > > > > Yes. In the probe() case, we must do things in this order: > > > > > > 1. brcm_pcie_setup() > > > 2. Turn on regulators > > > 3. brcm_pcie_linkup() > > > > Ah, I see, both 2) and 3) happen in brcm_pcie_add_bus: > > > > brcm_pcie_add_bus # bus->ops->add_bus > > pci_subdev_regulators_add_bus > > regulator_bulk_enable # turn on regulators > > brcm_pcie_linkup > > > > > Since the voltage regulators are turned on during enumeration, > > > pci_host_probe() must be invoked prior to 3. Before regulators, we > > > did not care. > > > > I guess in the pre-regulator case, i.e., pcie->sr not set, the power > > for downstream devices must always be on. > > > > > In the resume case, there is no enumeration of course but our driver > > > has a handle to the regulators and can turn them on/off w/o help. > > > > And I guess we don't need brcm_pcie_setup() in the resume path because > > suspend turns off power only for downstream devices, not for the root > > port itself, so the programming done by brcm_pcie_setup() doesn't need > > to be done again. > > I'm not sure I understand what you are saying -- brcm_pcie_setup() is > called by brcm_pcie_resume() > because it is needed. brcm_pcie_setup() isn't concerned with power it > just does the preparation > required before attempting link-up. Oh, sorry, I totally misread that. But I wonder about the fact that probe and resume do these in different orders: brcm_pcie_probe brcm_pcie_setup # setup pci_host_probe ... brcm_pcie_add_bus pci_subdev_regulators_add_bus regulator_bulk_enable # regulators on brcm_pcie_linkup # linkup brcm_pcie_resume regulator_bulk_enable # regulators on brcm_pcie_setup # setup brcm_pcie_linkup # linkup Maybe pci_subdev_regulators_add_bus() could be done directly from brcm_pcie_probe() instead of in brcm_pcie_add_bus()? If the regulators must be directly under the root port node in DT, it seems like it would be reasonable to look for them in the probe path, which seems like what pcie-dw-rockchip.c, pcie-tegra194.c, and pcie-rockchip-host.c do. Or maybe brcm_pcie_resume() should enable the regulators after brcm_pcie_setup() so it's the same order as the probe path? Bjorn
On Fri, Jul 8, 2022 at 3:59 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > On Fri, Jul 08, 2022 at 03:40:43PM -0400, Jim Quinlan wrote: > > On Fri, Jul 8, 2022 at 3:04 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > > On Fri, Jul 08, 2022 at 09:29:27AM -0400, Jim Quinlan wrote: > > > > On Wed, Jul 6, 2022 at 5:56 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > > > > On Fri, Jul 01, 2022 at 12:27:22PM -0400, Jim Quinlan wrote: > > > > > > We need to take some code in brcm_pcie_setup() and put it in a new function > > > > > > brcm_pcie_linkup(). In future commits the brcm_pcie_linkup() function will > > > > > > be called indirectly by pci_host_probe() as opposed to the host driver > > > > > > invoking it directly. > > > > > > > > > > > > Some code that was executed after the PCIe linkup is now placed so that it > > > > > > executes prior to linkup, since this code has to run prior to the > > > > > > invocation of pci_host_probe(). > > > > > > > > > > This says we need to move some code from brcm_pcie_setup() to > > > > > brcm_pcie_linkup(), but not *why* we need to do that. > > > > I will elaborate in the commit message. > > > > > > > > > > In brcm_pcie_resume(), they're called together: > > > > > > > > > > brcm_pcie_resume > > > > > brcm_pcie_setup > > > > > brcm_pcie_linkup > > > > > > > > > > In the probe path, they're not called together, but they're in the > > > > > same order: > > > > > > > > > > brcm_pcie_probe > > > > > brcm_pcie_setup > > > > > pci_host_probe > > > > > ... > > > > > brcm_pcie_add_bus # bus->ops->add_bus > > > > > brcm_pcie_linkup > > > > > > > > > > Is there something that must happen *between* them in the probe path? > > > > > > > > Yes. In the probe() case, we must do things in this order: > > > > > > > > 1. brcm_pcie_setup() > > > > 2. Turn on regulators > > > > 3. brcm_pcie_linkup() > > > > > > Ah, I see, both 2) and 3) happen in brcm_pcie_add_bus: > > > > > > brcm_pcie_add_bus # bus->ops->add_bus > > > pci_subdev_regulators_add_bus > > > regulator_bulk_enable # turn on regulators > > > brcm_pcie_linkup > > > > > > > Since the voltage regulators are turned on during enumeration, > > > > pci_host_probe() must be invoked prior to 3. Before regulators, we > > > > did not care. > > > > > > I guess in the pre-regulator case, i.e., pcie->sr not set, the power > > > for downstream devices must always be on. > > > > > > > In the resume case, there is no enumeration of course but our driver > > > > has a handle to the regulators and can turn them on/off w/o help. > > > > > > And I guess we don't need brcm_pcie_setup() in the resume path because > > > suspend turns off power only for downstream devices, not for the root > > > port itself, so the programming done by brcm_pcie_setup() doesn't need > > > to be done again. > > > > I'm not sure I understand what you are saying -- brcm_pcie_setup() is > > called by brcm_pcie_resume() > > because it is needed. brcm_pcie_setup() isn't concerned with power it > > just does the preparation > > required before attempting link-up. > > Oh, sorry, I totally misread that. > > But I wonder about the fact that probe and resume do these in > different orders: > > brcm_pcie_probe > brcm_pcie_setup # setup > pci_host_probe > ... > brcm_pcie_add_bus > pci_subdev_regulators_add_bus > regulator_bulk_enable # regulators on > brcm_pcie_linkup # linkup > > brcm_pcie_resume > regulator_bulk_enable # regulators on > brcm_pcie_setup # setup > brcm_pcie_linkup # linkup > brcm_pcie_setup() should be order-independent of brcm_pcie_linkup(), but your point is valid -- it is prudent to keep the orders consistent. Let me think about this. > Maybe pci_subdev_regulators_add_bus() could be done directly from > brcm_pcie_probe() instead of in brcm_pcie_add_bus()? > regulators must be directly under the root port node in DT, it seems > like it would be reasonable to look for them in the probe path, which > seems like what pcie-dw-rockchip.c, pcie-tegra194.c, and > pcie-rockchip-host.c do. At some point in the original patchset -- IIRC -- the RC driver was searching the DT tree for regulators. However, doing a "get" on these regulators is pretty much impossible if the "owning" device does not exist. I even had a version that partially created the downstream device; this pullreq was a mess and got feedback which put me on the current approach. Reviews suggested that the best location for the regulators should be located in the root port DT node(s). I agree with this. In addition, there was a request to allow multiple regulators to exist at each of the root ports in the downstream tree. So if the RC driver has to potentially add multiple buses. I really don't know how it would do that, and then call the pci_host_probe() w/o it failing. Perhaps this is what ACPI does before boot -- I'm guessing here -- but I would also guess that it is a decent amount of code as it is not far from doing enumeration. One thing I could do is to allow the port driver's suspend/resume to do the turning off/on of the regulators. There are two issues with this: (1) feedback suggested to put the code local to the Brcmstb driver and (2) the "ep wakeup_capable" code would also have to live in the port driver and I'm not sure this would be welcome. > > Or maybe brcm_pcie_resume() should enable the regulators after > brcm_pcie_setup() so it's the same order as the probe path? I think I'll do this. Thanks, Jim Quinlan Broadcom STB > > Bjorn
On Fri, Jul 08, 2022 at 04:38:30PM -0400, Jim Quinlan wrote: > On Fri, Jul 8, 2022 at 3:59 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > On Fri, Jul 08, 2022 at 03:40:43PM -0400, Jim Quinlan wrote: > > > On Fri, Jul 8, 2022 at 3:04 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > > > On Fri, Jul 08, 2022 at 09:29:27AM -0400, Jim Quinlan wrote: > > > > > On Wed, Jul 6, 2022 at 5:56 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > > > > > On Fri, Jul 01, 2022 at 12:27:22PM -0400, Jim Quinlan wrote: > > > > > > > We need to take some code in brcm_pcie_setup() and put it in a new function > > > > > > > brcm_pcie_linkup(). In future commits the brcm_pcie_linkup() function will > > > > > > > be called indirectly by pci_host_probe() as opposed to the host driver > > > > > > > invoking it directly. > > > > > > > > > > > > > > Some code that was executed after the PCIe linkup is now placed so that it > > > > > > > executes prior to linkup, since this code has to run prior to the > > > > > > > invocation of pci_host_probe(). > > > > > > > > > > > > This says we need to move some code from brcm_pcie_setup() to > > > > > > brcm_pcie_linkup(), but not *why* we need to do that. > > > > > I will elaborate in the commit message. > > > > > > > > > > > > In brcm_pcie_resume(), they're called together: > > > > > > > > > > > > brcm_pcie_resume > > > > > > brcm_pcie_setup > > > > > > brcm_pcie_linkup > > > > > > > > > > > > In the probe path, they're not called together, but they're in the > > > > > > same order: > > > > > > > > > > > > brcm_pcie_probe > > > > > > brcm_pcie_setup > > > > > > pci_host_probe > > > > > > ... > > > > > > brcm_pcie_add_bus # bus->ops->add_bus > > > > > > brcm_pcie_linkup > > > > > > > > > > > > Is there something that must happen *between* them in the probe path? > > > > > > > > > > Yes. In the probe() case, we must do things in this order: > > > > > > > > > > 1. brcm_pcie_setup() > > > > > 2. Turn on regulators > > > > > 3. brcm_pcie_linkup() > > > > > > > > Ah, I see, both 2) and 3) happen in brcm_pcie_add_bus: > > > > > > > > brcm_pcie_add_bus # bus->ops->add_bus > > > > pci_subdev_regulators_add_bus > > > > regulator_bulk_enable # turn on regulators > > > > brcm_pcie_linkup > > > > > > > > > Since the voltage regulators are turned on during enumeration, > > > > > pci_host_probe() must be invoked prior to 3. Before regulators, we > > > > > did not care. > > > > > > > > I guess in the pre-regulator case, i.e., pcie->sr not set, the power > > > > for downstream devices must always be on. > > > > > > > > > In the resume case, there is no enumeration of course but our driver > > > > > has a handle to the regulators and can turn them on/off w/o help. > > > > > > > > And I guess we don't need brcm_pcie_setup() in the resume path because > > > > suspend turns off power only for downstream devices, not for the root > > > > port itself, so the programming done by brcm_pcie_setup() doesn't need > > > > to be done again. > > > > > > I'm not sure I understand what you are saying -- brcm_pcie_setup() is > > > called by brcm_pcie_resume() > > > because it is needed. brcm_pcie_setup() isn't concerned with power it > > > just does the preparation > > > required before attempting link-up. > > > > Oh, sorry, I totally misread that. > > > > But I wonder about the fact that probe and resume do these in > > different orders: > > > > brcm_pcie_probe > > brcm_pcie_setup # setup > > pci_host_probe > > ... > > brcm_pcie_add_bus > > pci_subdev_regulators_add_bus > > regulator_bulk_enable # regulators on > > brcm_pcie_linkup # linkup > > > > brcm_pcie_resume > > regulator_bulk_enable # regulators on > > brcm_pcie_setup # setup > > brcm_pcie_linkup # linkup > > > brcm_pcie_setup() should be order-independent of brcm_pcie_linkup(), > but your point is valid -- it is prudent to keep the orders > consistent. Let me think > about this. > > > Maybe pci_subdev_regulators_add_bus() could be done directly from > > brcm_pcie_probe() instead of in brcm_pcie_add_bus()? > > regulators must be directly under the root port node in DT, it seems > > like it would be reasonable to look for them in the probe path, which > > seems like what pcie-dw-rockchip.c, pcie-tegra194.c, and > > pcie-rockchip-host.c do. > At some point in the original patchset -- IIRC -- the RC driver was > searching the DT > tree for regulators. However, doing a "get" on these regulators is pretty much > impossible if the "owning" device does not exist. I even had a version that > partially created the downstream device; this pullreq was a mess and > got feedback which put me on the current approach. Ah, I suppose because the regulators are not under the host bridge itself, but under the *root port*, which is a PCI device that doesn't exist until we enumerate it. Although I guess the root port is described in the DT, and the regulators are connected with that DT description, not directly with the pci_dev. > Reviews suggested that the best location for the regulators should be located > in the root port DT node(s). I agree with this. In addition, there > was a request to allow multiple regulators > to exist at each of the root ports in the downstream tree. Makes sense. > So if the RC driver > has to potentially add multiple buses. I really don't know how it > would do that, > and then call the pci_host_probe() w/o it failing. Perhaps this is what ACPI > does before boot -- I'm guessing here -- but I would also guess that it is > a decent amount of code as it is not far from doing enumeration. > > One thing I could do is to allow the port driver's suspend/resume to do the > turning off/on of the regulators. There are two issues with this: (1) > feedback suggested > to put the code local to the Brcmstb driver and (2) the "ep wakeup_capable" > code would also have to live in the port driver and I'm not sure this > would be welcome. > > > Or maybe brcm_pcie_resume() should enable the regulators after > > brcm_pcie_setup() so it's the same order as the probe path? > I think I'll do this. Yep, sounds like the right thing. Bjorn
diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c index e61058e13818..2bf5cc399fd0 100644 --- a/drivers/pci/controller/pcie-brcmstb.c +++ b/drivers/pci/controller/pcie-brcmstb.c @@ -926,16 +926,9 @@ static inline int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie, static int brcm_pcie_setup(struct brcm_pcie *pcie) { - struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie); u64 rc_bar2_offset, rc_bar2_size; void __iomem *base = pcie->base; - struct device *dev = pcie->dev; - struct resource_entry *entry; - bool ssc_good = false; - struct resource *res; - int num_out_wins = 0; - u16 nlw, cls, lnksta; - int i, ret, memc; + int ret, memc; u32 tmp, burst, aspm_support; /* Reset the bridge */ @@ -1025,6 +1018,40 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) if (pcie->gen) brcm_pcie_set_gen(pcie, pcie->gen); + /* Don't advertise L0s capability if 'aspm-no-l0s' */ + aspm_support = PCIE_LINK_STATE_L1; + if (!of_property_read_bool(pcie->np, "aspm-no-l0s")) + aspm_support |= PCIE_LINK_STATE_L0S; + tmp = readl(base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); + u32p_replace_bits(&tmp, aspm_support, + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK); + writel(tmp, base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); + + /* + * For config space accesses on the RC, show the right class for + * a PCIe-PCIe bridge (the default setting is to be EP mode). + */ + tmp = readl(base + PCIE_RC_CFG_PRIV1_ID_VAL3); + u32p_replace_bits(&tmp, 0x060400, + PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK); + writel(tmp, base + PCIE_RC_CFG_PRIV1_ID_VAL3); + + return 0; +} + +static int brcm_pcie_linkup(struct brcm_pcie *pcie) +{ + struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie); + struct device *dev = pcie->dev; + void __iomem *base = pcie->base; + struct resource_entry *entry; + struct resource *res; + int num_out_wins = 0; + u16 nlw, cls, lnksta; + bool ssc_good = false; + u32 tmp; + int ret, i; + /* Unassert the fundamental reset */ pcie->perst_set(pcie, 0); @@ -1075,24 +1102,6 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) num_out_wins++; } - /* Don't advertise L0s capability if 'aspm-no-l0s' */ - aspm_support = PCIE_LINK_STATE_L1; - if (!of_property_read_bool(pcie->np, "aspm-no-l0s")) - aspm_support |= PCIE_LINK_STATE_L0S; - tmp = readl(base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); - u32p_replace_bits(&tmp, aspm_support, - PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK); - writel(tmp, base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); - - /* - * For config space accesses on the RC, show the right class for - * a PCIe-PCIe bridge (the default setting is to be EP mode). - */ - tmp = readl(base + PCIE_RC_CFG_PRIV1_ID_VAL3); - u32p_replace_bits(&tmp, 0x060400, - PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK); - writel(tmp, base + PCIE_RC_CFG_PRIV1_ID_VAL3); - if (pcie->ssc) { ret = brcm_pcie_set_ssc(pcie); if (ret == 0) @@ -1281,6 +1290,10 @@ static int brcm_pcie_resume(struct device *dev) if (ret) goto err_reset; + ret = brcm_pcie_linkup(pcie); + if (ret) + goto err_reset; + if (pcie->msi) brcm_msi_set_regs(pcie->msi); @@ -1398,6 +1411,10 @@ static int brcm_pcie_probe(struct platform_device *pdev) if (ret) goto fail; + ret = brcm_pcie_linkup(pcie); + if (ret) + goto fail; + pcie->hw_rev = readl(pcie->base + PCIE_MISC_REVISION); if (pcie->type == BCM4908 && pcie->hw_rev >= BRCM_PCIE_HW_REV_3_20) { dev_err(pcie->dev, "hardware revision with unsupported PERST# setup\n");
We need to take some code in brcm_pcie_setup() and put it in a new function brcm_pcie_linkup(). In future commits the brcm_pcie_linkup() function will be called indirectly by pci_host_probe() as opposed to the host driver invoking it directly. Some code that was executed after the PCIe linkup is now placed so that it executes prior to linkup, since this code has to run prior to the invocation of pci_host_probe(). Link: https://lore.kernel.org/r/20220106160332.2143-5-jim2101024@gmail.com Signed-off-by: Jim Quinlan <jim2101024@gmail.com> --- drivers/pci/controller/pcie-brcmstb.c | 69 +++++++++++++++++---------- 1 file changed, 43 insertions(+), 26 deletions(-)