On Fri, Sep 13, 2019 at 04:09:50PM +0530, Pankaj Dubey wrote: > From: Anvesh Salveru <anvesh.s@xxxxxxxxxxx> > > In some platforms, PCIe PHY may have issues which will prevent linkup > to happen in GEN3 or higher speed. In case equalization fails, link will > fallback to GEN1. > > DesignWare controller gives flexibility to disable GEN3 equalization > completely or only phase 2 and 3 of equalization. > > This patch enables the DesignWare driver to disable the PCIe GEN3 > equalization by enabling one of the following quirks: > - DWC_EQUALIZATION_DISABLE: To disable GEN3 equalization all phases > - DWC_EQ_PHASE_2_3_DISABLE: To disable GEN3 equalization phase 2 & 3 > > Platform drivers can set these quirks via "quirk" variable of "dw_pcie" > struct. > > Signed-off-by: Anvesh Salveru <anvesh.s@xxxxxxxxxxx> > Signed-off-by: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx> > --- > Patchset v1 can be found at: > - 1/2: https://lkml.org/lkml/2019/9/10/443 > - 2/2: https://lkml.org/lkml/2019/9/10/444 > > Changes w.r.t v1: > - Squashed two patches from v1 into one as suggested by Gustavo > - Addressed review comments from Andrew > > drivers/pci/controller/dwc/pcie-designware.c | 12 ++++++++++++ > drivers/pci/controller/dwc/pcie-designware.h | 9 +++++++++ > 2 files changed, 21 insertions(+) > > diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c > index 7d25102..97fb18d 100644 > --- a/drivers/pci/controller/dwc/pcie-designware.c > +++ b/drivers/pci/controller/dwc/pcie-designware.c > @@ -466,4 +466,16 @@ void dw_pcie_setup(struct dw_pcie *pci) > break; > } > dw_pcie_writel_dbi(pci, PCIE_LINK_WIDTH_SPEED_CONTROL, val); > + > + if (pci->quirk & DWC_EQUALIZATION_DISABLE) { > + val = dw_pcie_readl_dbi(pci, PCIE_PORT_GEN3_RELATED); > + val |= PORT_LOGIC_GEN3_EQ_DISABLE; > + dw_pcie_writel_dbi(pci, PCIE_PORT_GEN3_RELATED, val); > + } > + > + if (pci->quirk & DWC_EQ_PHASE_2_3_DISABLE) { > + val = dw_pcie_readl_dbi(pci, PCIE_PORT_GEN3_RELATED); > + val |= PORT_LOGIC_GEN3_EQ_PHASE_2_3_DISABLE; > + dw_pcie_writel_dbi(pci, PCIE_PORT_GEN3_RELATED, val); > + } > } > diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h > index ffed084..e428b62 100644 > --- a/drivers/pci/controller/dwc/pcie-designware.h > +++ b/drivers/pci/controller/dwc/pcie-designware.h > @@ -29,6 +29,10 @@ > #define LINK_WAIT_MAX_IATU_RETRIES 5 > #define LINK_WAIT_IATU 9 > > +/* Parameters for GEN3 related quirks */ > +#define DWC_EQUALIZATION_DISABLE BIT(1) > +#define DWC_EQ_PHASE_2_3_DISABLE BIT(2) > + > /* Synopsys-specific PCIe configuration registers */ > #define PCIE_PORT_LINK_CONTROL 0x710 > #define PORT_LINK_MODE_MASK GENMASK(21, 16) > @@ -60,6 +64,10 @@ > #define PCIE_MSI_INTR0_MASK 0x82C > #define PCIE_MSI_INTR0_STATUS 0x830 > > +#define PCIE_PORT_GEN3_RELATED 0x890 I hadn't noticed this in the previous version - what is the proper name for this register? Does it end in _RELATED? Thanks, Andrew Murray > +#define PORT_LOGIC_GEN3_EQ_PHASE_2_3_DISABLE BIT(9) > +#define PORT_LOGIC_GEN3_EQ_DISABLE BIT(16) > + > #define PCIE_ATU_VIEWPORT 0x900 > #define PCIE_ATU_REGION_INBOUND BIT(31) > #define PCIE_ATU_REGION_OUTBOUND 0 > @@ -244,6 +252,7 @@ struct dw_pcie { > struct dw_pcie_ep ep; > const struct dw_pcie_ops *ops; > unsigned int version; > + unsigned int quirk; > }; > > #define to_dw_pcie_from_pp(port) container_of((port), struct dw_pcie, pp) > -- > 2.7.4 >
