| Message ID | 20240111152517.1881382-1-ajayagarwal@google.com |
|---|---|
| State | New |
| Headers | show |
| Series | PCI: dwc: Wait for link up only if link is started | expand |
On Thu, Jan 11, 2024 at 08:55:17PM +0530, Ajay Agarwal wrote: > In dw_pcie_host_init() regardless of whether the link has been > started or not, the code waits for the link to come up. Even in > cases where start_link() is not defined the code ends up spinning > in a loop for 1 second. Since in some systems dw_pcie_host_init() > gets called during probe, this one second loop for each pcie > interface instance ends up extending the boot time. > > Wait for the link up in only if the start_link() is defined. > > Signed-off-by: Ajay Agarwal <ajayagarwal@google.com> This is clearly not v1. Either this patch has to be a RESEND or v2. And the changelog should mention what happened to the earlier version (revert history etc...) Also, I provided feedback on the revert patch that you have completely ignored [1]. If you do not agree with those, it is fine, but you should justify first. - Mani [1] https://lore.kernel.org/linux-pci/20230711073719.GA36617@thinkpad/ > --- > .../pci/controller/dwc/pcie-designware-host.c | 12 +++++++---- > drivers/pci/controller/dwc/pcie-designware.c | 20 ++++++++++++------- > drivers/pci/controller/dwc/pcie-designware.h | 1 + > 3 files changed, 22 insertions(+), 11 deletions(-) > > diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c > index 7991f0e179b2..e53132663d1d 100644 > --- a/drivers/pci/controller/dwc/pcie-designware-host.c > +++ b/drivers/pci/controller/dwc/pcie-designware-host.c > @@ -487,14 +487,18 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp) > if (ret) > goto err_remove_edma; > > - if (!dw_pcie_link_up(pci)) { > + if (dw_pcie_link_up(pci)) { > + dw_pcie_print_link_status(pci); > + } else { > ret = dw_pcie_start_link(pci); > if (ret) > goto err_remove_edma; > - } > > - /* Ignore errors, the link may come up later */ > - dw_pcie_wait_for_link(pci); > + if (pci->ops && pci->ops->start_link) { > + /* Ignore errors, the link may come up later */ > + dw_pcie_wait_for_link(pci); > + } > + } > > bridge->sysdata = pp; > > diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c > index 250cf7f40b85..c067d2e960cf 100644 > --- a/drivers/pci/controller/dwc/pcie-designware.c > +++ b/drivers/pci/controller/dwc/pcie-designware.c > @@ -645,9 +645,20 @@ void dw_pcie_disable_atu(struct dw_pcie *pci, u32 dir, int index) > dw_pcie_writel_atu(pci, dir, index, PCIE_ATU_REGION_CTRL2, 0); > } > > -int dw_pcie_wait_for_link(struct dw_pcie *pci) > +void dw_pcie_print_link_status(struct dw_pcie *pci) > { > u32 offset, val; > + > + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); > + val = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA); > + > + dev_info(pci->dev, "PCIe Gen.%u x%u link up\n", > + FIELD_GET(PCI_EXP_LNKSTA_CLS, val), > + FIELD_GET(PCI_EXP_LNKSTA_NLW, val)); > +} > + > +int dw_pcie_wait_for_link(struct dw_pcie *pci) > +{ > int retries; > > /* Check if the link is up or not */ > @@ -663,12 +674,7 @@ int dw_pcie_wait_for_link(struct dw_pcie *pci) > return -ETIMEDOUT; > } > > - offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); > - val = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA); > - > - dev_info(pci->dev, "PCIe Gen.%u x%u link up\n", > - FIELD_GET(PCI_EXP_LNKSTA_CLS, val), > - FIELD_GET(PCI_EXP_LNKSTA_NLW, val)); > + dw_pcie_print_link_status(pci); > > return 0; > } > diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h > index 55ff76e3d384..164214a7219a 100644 > --- a/drivers/pci/controller/dwc/pcie-designware.h > +++ b/drivers/pci/controller/dwc/pcie-designware.h > @@ -447,6 +447,7 @@ void dw_pcie_setup(struct dw_pcie *pci); > void dw_pcie_iatu_detect(struct dw_pcie *pci); > int dw_pcie_edma_detect(struct dw_pcie *pci); > void dw_pcie_edma_remove(struct dw_pcie *pci); > +void dw_pcie_print_link_status(struct dw_pcie *pci); > > int dw_pcie_suspend_noirq(struct dw_pcie *pci); > int dw_pcie_resume_noirq(struct dw_pcie *pci); > -- > 2.43.0.275.g3460e3d667-goog >
On Fri, Jan 12, 2024 at 10:58:16AM +0530, Manivannan Sadhasivam wrote: > On Thu, Jan 11, 2024 at 08:55:17PM +0530, Ajay Agarwal wrote: > > In dw_pcie_host_init() regardless of whether the link has been > > started or not, the code waits for the link to come up. Even in > > cases where start_link() is not defined the code ends up spinning > > in a loop for 1 second. Since in some systems dw_pcie_host_init() > > gets called during probe, this one second loop for each pcie > > interface instance ends up extending the boot time. > > > > Wait for the link up in only if the start_link() is defined. > > > > Signed-off-by: Ajay Agarwal <ajayagarwal@google.com> > > This is clearly not v1. Either this patch has to be a RESEND or v2. And the > changelog should mention what happened to the earlier version (revert history > etc...) > Sorry about that. I will create a v5 since the v4 version of this patch was applied but then reverted. Will add revert history, reason and changelog from v4 to the v5 description. > Also, I provided feedback on the revert patch that you have completely ignored > [1]. If you do not agree with those, it is fine, but you should justify first. > > - Mani > > [1] https://lore.kernel.org/linux-pci/20230711073719.GA36617@thinkpad/ > Sure. Responded to the questions on the thread you mentioned. > > --- > > .../pci/controller/dwc/pcie-designware-host.c | 12 +++++++---- > > drivers/pci/controller/dwc/pcie-designware.c | 20 ++++++++++++------- > > drivers/pci/controller/dwc/pcie-designware.h | 1 + > > 3 files changed, 22 insertions(+), 11 deletions(-) > > > > diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c > > index 7991f0e179b2..e53132663d1d 100644 > > --- a/drivers/pci/controller/dwc/pcie-designware-host.c > > +++ b/drivers/pci/controller/dwc/pcie-designware-host.c > > @@ -487,14 +487,18 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp) > > if (ret) > > goto err_remove_edma; > > > > - if (!dw_pcie_link_up(pci)) { > > + if (dw_pcie_link_up(pci)) { > > + dw_pcie_print_link_status(pci); > > + } else { > > ret = dw_pcie_start_link(pci); > > if (ret) > > goto err_remove_edma; > > - } > > > > - /* Ignore errors, the link may come up later */ > > - dw_pcie_wait_for_link(pci); > > + if (pci->ops && pci->ops->start_link) { > > + /* Ignore errors, the link may come up later */ > > + dw_pcie_wait_for_link(pci); > > + } > > + } > > > > bridge->sysdata = pp; > > > > diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c > > index 250cf7f40b85..c067d2e960cf 100644 > > --- a/drivers/pci/controller/dwc/pcie-designware.c > > +++ b/drivers/pci/controller/dwc/pcie-designware.c > > @@ -645,9 +645,20 @@ void dw_pcie_disable_atu(struct dw_pcie *pci, u32 dir, int index) > > dw_pcie_writel_atu(pci, dir, index, PCIE_ATU_REGION_CTRL2, 0); > > } > > > > -int dw_pcie_wait_for_link(struct dw_pcie *pci) > > +void dw_pcie_print_link_status(struct dw_pcie *pci) > > { > > u32 offset, val; > > + > > + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); > > + val = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA); > > + > > + dev_info(pci->dev, "PCIe Gen.%u x%u link up\n", > > + FIELD_GET(PCI_EXP_LNKSTA_CLS, val), > > + FIELD_GET(PCI_EXP_LNKSTA_NLW, val)); > > +} > > + > > +int dw_pcie_wait_for_link(struct dw_pcie *pci) > > +{ > > int retries; > > > > /* Check if the link is up or not */ > > @@ -663,12 +674,7 @@ int dw_pcie_wait_for_link(struct dw_pcie *pci) > > return -ETIMEDOUT; > > } > > > > - offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); > > - val = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA); > > - > > - dev_info(pci->dev, "PCIe Gen.%u x%u link up\n", > > - FIELD_GET(PCI_EXP_LNKSTA_CLS, val), > > - FIELD_GET(PCI_EXP_LNKSTA_NLW, val)); > > + dw_pcie_print_link_status(pci); > > > > return 0; > > } > > diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h > > index 55ff76e3d384..164214a7219a 100644 > > --- a/drivers/pci/controller/dwc/pcie-designware.h > > +++ b/drivers/pci/controller/dwc/pcie-designware.h > > @@ -447,6 +447,7 @@ void dw_pcie_setup(struct dw_pcie *pci); > > void dw_pcie_iatu_detect(struct dw_pcie *pci); > > int dw_pcie_edma_detect(struct dw_pcie *pci); > > void dw_pcie_edma_remove(struct dw_pcie *pci); > > +void dw_pcie_print_link_status(struct dw_pcie *pci); > > > > int dw_pcie_suspend_noirq(struct dw_pcie *pci); > > int dw_pcie_resume_noirq(struct dw_pcie *pci); > > -- > > 2.43.0.275.g3460e3d667-goog > > > > -- > மணிவண்ணன் சதாசிவம்
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index 7991f0e179b2..e53132663d1d 100644 --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -487,14 +487,18 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp) if (ret) goto err_remove_edma; - if (!dw_pcie_link_up(pci)) { + if (dw_pcie_link_up(pci)) { + dw_pcie_print_link_status(pci); + } else { ret = dw_pcie_start_link(pci); if (ret) goto err_remove_edma; - } - /* Ignore errors, the link may come up later */ - dw_pcie_wait_for_link(pci); + if (pci->ops && pci->ops->start_link) { + /* Ignore errors, the link may come up later */ + dw_pcie_wait_for_link(pci); + } + } bridge->sysdata = pp; diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index 250cf7f40b85..c067d2e960cf 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -645,9 +645,20 @@ void dw_pcie_disable_atu(struct dw_pcie *pci, u32 dir, int index) dw_pcie_writel_atu(pci, dir, index, PCIE_ATU_REGION_CTRL2, 0); } -int dw_pcie_wait_for_link(struct dw_pcie *pci) +void dw_pcie_print_link_status(struct dw_pcie *pci) { u32 offset, val; + + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); + val = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA); + + dev_info(pci->dev, "PCIe Gen.%u x%u link up\n", + FIELD_GET(PCI_EXP_LNKSTA_CLS, val), + FIELD_GET(PCI_EXP_LNKSTA_NLW, val)); +} + +int dw_pcie_wait_for_link(struct dw_pcie *pci) +{ int retries; /* Check if the link is up or not */ @@ -663,12 +674,7 @@ int dw_pcie_wait_for_link(struct dw_pcie *pci) return -ETIMEDOUT; } - offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); - val = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA); - - dev_info(pci->dev, "PCIe Gen.%u x%u link up\n", - FIELD_GET(PCI_EXP_LNKSTA_CLS, val), - FIELD_GET(PCI_EXP_LNKSTA_NLW, val)); + dw_pcie_print_link_status(pci); return 0; } diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index 55ff76e3d384..164214a7219a 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -447,6 +447,7 @@ void dw_pcie_setup(struct dw_pcie *pci); void dw_pcie_iatu_detect(struct dw_pcie *pci); int dw_pcie_edma_detect(struct dw_pcie *pci); void dw_pcie_edma_remove(struct dw_pcie *pci); +void dw_pcie_print_link_status(struct dw_pcie *pci); int dw_pcie_suspend_noirq(struct dw_pcie *pci); int dw_pcie_resume_noirq(struct dw_pcie *pci);
In dw_pcie_host_init() regardless of whether the link has been started or not, the code waits for the link to come up. Even in cases where start_link() is not defined the code ends up spinning in a loop for 1 second. Since in some systems dw_pcie_host_init() gets called during probe, this one second loop for each pcie interface instance ends up extending the boot time. Wait for the link up in only if the start_link() is defined. Signed-off-by: Ajay Agarwal <ajayagarwal@google.com> --- .../pci/controller/dwc/pcie-designware-host.c | 12 +++++++---- drivers/pci/controller/dwc/pcie-designware.c | 20 ++++++++++++------- drivers/pci/controller/dwc/pcie-designware.h | 1 + 3 files changed, 22 insertions(+), 11 deletions(-)