> -----Original Message-----
> From: Andrew Murray <andrew.murray@xxxxxxx>
> Sent: Monday, October 21, 2019 7:34 PM
> To: Anvesh Salveru <anvesh.s@xxxxxxxxxxx>
> Cc: linux-pci@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> bhelgaas@xxxxxxxxxx; gustavo.pimentel@xxxxxxxxxxxx;
> jingoohan1@xxxxxxxxx; lorenzo.pieralisi@xxxxxxx; Pankaj Dubey
> <pankaj.dubey@xxxxxxxxxxx>
> Subject: Re: [PATCH 2/2] PCI: dwc: Add support to handle ZRX-DC Compliant
> PHYs
>
> On Mon, Oct 21, 2019 at 05:59:53PM +0530, Anvesh Salveru wrote:
> > Many platforms use DesignWare controller but the PHY can be different
> > in different platforms. If the PHY is compliant is to ZRX-DC
> > specification
>
> s/is to/to the/
OK
>
> > it helps in low power consumption during power states.
>
> s/in low/lower/
>
OK
> >
> > If current data rate is 8.0 GT/s or higher and PHY is not compliant to
> > ZRX-DC specification, then after every 100ms link should transition to
> > recovery state during the low power states.
> >
> > DesignWare controller provides GEN3_ZRXDC_NONCOMPL field in
> > GEN3_RELATED_OFF to specify about ZRX-DC compliant PHY.
> >
> > Platforms with ZRX-DC compliant PHY can set "snps,phy-zrxdc-compliant"
> > property in controller DT node to specify this property to the
controller.
> >
> > Signed-off-by: Anvesh Salveru <anvesh.s@xxxxxxxxxxx>
> > Signed-off-by: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx>
> > ---
> > drivers/pci/controller/dwc/pcie-designware.c | 7 +++++++
> > drivers/pci/controller/dwc/pcie-designware.h | 3 +++
> > 2 files changed, 10 insertions(+)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.c
> > b/drivers/pci/controller/dwc/pcie-designware.c
> > index 820488dfeaed..6560d9f765d7 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware.c
> > @@ -556,4 +556,11 @@ void dw_pcie_setup(struct dw_pcie *pci)
> > PCIE_PL_CHK_REG_CHK_REG_START;
> > dw_pcie_writel_dbi(pci, PCIE_PL_CHK_REG_CONTROL_STATUS,
> val);
> > }
> > +
> > + if (of_property_read_bool(np, "snps,phy-zrxdc-compliant")) {
> > + val = dw_pcie_readl_dbi(pci, PCIE_PORT_GEN3_RELATED);
> > + val &= ~PORT_LOGIC_GEN3_ZRXDC_NONCOMPL;
> > + dw_pcie_writel_dbi(pci, PCIE_PORT_GEN3_RELATED, val);
> > + }
> > +
>
> Given that this duplicates tegra_pcie_prepare_host in pcie-tegra194.c, can
we
> update that driver to adopt this new binding?
>
Yes, Thanks for highlighting this. Otherwise I was worried that we have one
more patch without real user :)
We will update pcie-tegra194.c driver and post the patch to adopt this
binding.
> Thanks,
>
> Andrew Murray
>
> > }
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.h
> > b/drivers/pci/controller/dwc/pcie-designware.h
> > index 5a18e94e52c8..427a55ec43c6 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.h
> > +++ b/drivers/pci/controller/dwc/pcie-designware.h
> > @@ -60,6 +60,9 @@
> > #define PCIE_MSI_INTR0_MASK 0x82C
> > #define PCIE_MSI_INTR0_STATUS 0x830
> >
> > +#define PCIE_PORT_GEN3_RELATED 0x890
> > +#define PORT_LOGIC_GEN3_ZRXDC_NONCOMPL BIT(0)
> > +
> > #define PCIE_ATU_VIEWPORT 0x900
> > #define PCIE_ATU_REGION_INBOUND BIT(31)
> > #define PCIE_ATU_REGION_OUTBOUND 0
> > --
> > 2.17.1
> >
