| Message ID | 20230922065331.3806925-4-yoshihiro.shimoda.uh@renesas.com |
|---|---|
| State | New |
| Headers | show |
| Series | PCI: dwc: rcar-gen4: Add R-Car Gen4 PCIe support | expand |
On Fri, Sep 22, 2023 at 03:53:18PM +0900, Yoshihiro Shimoda wrote: > Update dw_pcie_link_set_max_link_width() to set PCI_EXP_LNKCAP_MLW. > > In accordance with the DW PCIe RC/EP HW manuals [1,2,3,...] aside with > the PORT_LINK_CTRL_OFF.LINK_CAPABLE and GEN2_CTRL_OFF.NUM_OF_LANES[8:0] > field there is another one which needs to be updated. > > It's LINK_CAPABILITIES_REG.PCIE_CAP_MAX_LINK_WIDTH. If it isn't done at > the very least the maximum link-width capability CSR won't expose the > actual maximum capability. > > [1] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, > Version 4.60a, March 2015, p.1032 > [2] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, > Version 4.70a, March 2016, p.1065 > [3] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, > Version 4.90a, March 2016, p.1057 > ... > [X] DesignWare Cores PCI Express Controller Databook - DWC PCIe Endpoint, > Version 5.40a, March 2019, p.1396 > [X+1] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, > Version 5.40a, March 2019, p.1266 > > [kwilczynski: commit log] > Link: https://lore.kernel.org/linux-pci/20230825093219.2685912-8-yoshihiro.shimoda.uh@renesas.com > Suggested-by: Serge Semin <fancer.lancer@gmail.com> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Same comment about s-o-b. - Mani > Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org> > Reviewed-by: Serge Semin <fancer.lancer@gmail.com> > --- > drivers/pci/controller/dwc/pcie-designware.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c > index da4aba4aee62..2b60d20dfdf5 100644 > --- a/drivers/pci/controller/dwc/pcie-designware.c > +++ b/drivers/pci/controller/dwc/pcie-designware.c > @@ -734,7 +734,8 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen) > > static void dw_pcie_link_set_max_link_width(struct dw_pcie *pci, u32 num_lanes) > { > - u32 lwsc, plc; > + u32 lnkcap, lwsc, plc; > + u8 cap; > > if (!num_lanes) > return; > @@ -770,6 +771,12 @@ static void dw_pcie_link_set_max_link_width(struct dw_pcie *pci, u32 num_lanes) > } > dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, plc); > dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, lwsc); > + > + cap = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); > + lnkcap = dw_pcie_readl_dbi(pci, cap + PCI_EXP_LNKCAP); > + lnkcap &= ~PCI_EXP_LNKCAP_MLW; > + lnkcap |= FIELD_PREP(PCI_EXP_LNKCAP_MLW, num_lanes); > + dw_pcie_writel_dbi(pci, cap + PCI_EXP_LNKCAP, lnkcap); > } > > void dw_pcie_iatu_detect(struct dw_pcie *pci) > -- > 2.25.1 >
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index da4aba4aee62..2b60d20dfdf5 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -734,7 +734,8 @@ static void dw_pcie_link_set_max_speed(struct dw_pcie *pci, u32 link_gen) static void dw_pcie_link_set_max_link_width(struct dw_pcie *pci, u32 num_lanes) { - u32 lwsc, plc; + u32 lnkcap, lwsc, plc; + u8 cap; if (!num_lanes) return; @@ -770,6 +771,12 @@ static void dw_pcie_link_set_max_link_width(struct dw_pcie *pci, u32 num_lanes) } dw_pcie_writel_dbi(pci, PCIE_PORT_LINK_CONTROL, plc); dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, lwsc); + + cap = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); + lnkcap = dw_pcie_readl_dbi(pci, cap + PCI_EXP_LNKCAP); + lnkcap &= ~PCI_EXP_LNKCAP_MLW; + lnkcap |= FIELD_PREP(PCI_EXP_LNKCAP_MLW, num_lanes); + dw_pcie_writel_dbi(pci, cap + PCI_EXP_LNKCAP, lnkcap); } void dw_pcie_iatu_detect(struct dw_pcie *pci)
Update dw_pcie_link_set_max_link_width() to set PCI_EXP_LNKCAP_MLW. In accordance with the DW PCIe RC/EP HW manuals [1,2,3,...] aside with the PORT_LINK_CTRL_OFF.LINK_CAPABLE and GEN2_CTRL_OFF.NUM_OF_LANES[8:0] field there is another one which needs to be updated. It's LINK_CAPABILITIES_REG.PCIE_CAP_MAX_LINK_WIDTH. If it isn't done at the very least the maximum link-width capability CSR won't expose the actual maximum capability. [1] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, Version 4.60a, March 2015, p.1032 [2] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, Version 4.70a, March 2016, p.1065 [3] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, Version 4.90a, March 2016, p.1057 ... [X] DesignWare Cores PCI Express Controller Databook - DWC PCIe Endpoint, Version 5.40a, March 2019, p.1396 [X+1] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port, Version 5.40a, March 2019, p.1266 [kwilczynski: commit log] Link: https://lore.kernel.org/linux-pci/20230825093219.2685912-8-yoshihiro.shimoda.uh@renesas.com Suggested-by: Serge Semin <fancer.lancer@gmail.com> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org> Reviewed-by: Serge Semin <fancer.lancer@gmail.com> --- drivers/pci/controller/dwc/pcie-designware.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)