Re: [PATCH] usb: xhci: Workaround for S3 issue on AMD SNPS 3.0 xHC

[Singh, Sandeep]

Hi Greg,

On 10/23/2020 6:03 PM, Greg KH wrote:
> [CAUTION: External Email]
>
> On Fri, Oct 23, 2020 at 05:57:13PM +0530, Sandeep Singh wrote:
> > From: Sandeep Singh <sandeep.singh@xxxxxxx>
> >
> > On some platform of AMD, S3 fails with HCE and SRE errors. To fix this,
> > need to disable a bit which is enable in sparse controller.
> >
> > Signed-off-by: Sanket Goswami <Sanket.Goswami@xxxxxxx>
> > Signed-off-by: Sandeep Singh <sandeep.singh@xxxxxxx>
> > ---
> >   drivers/usb/host/xhci-pci.c | 17 +++++++++++++++++
> >   1 file changed, 17 insertions(+)
> >
> > diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
> > index c26c06e5c88c..bf89172c43ca 100644
> > --- a/drivers/usb/host/xhci-pci.c
> > +++ b/drivers/usb/host/xhci-pci.c
> > @@ -23,6 +23,8 @@
> >   #define SSIC_PORT_CFG2_OFFSET        0x30
> >   #define PROG_DONE            (1 << 30)
> >   #define SSIC_PORT_UNUSED     (1 << 31)
> > +#define SPARSE_DISABLE_BIT   17
> > +#define SPARSE_CNTL_ENABLE   0xC12C
> >
> >   /* Device for a quirk */
> >   #define PCI_VENDOR_ID_FRESCO_LOGIC   0x1b73
> > @@ -161,6 +163,9 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
> >            (pdev->device == 0x15e0 || pdev->device == 0x15e1))
> >                xhci->quirks |= XHCI_SNPS_BROKEN_SUSPEND;
> >
> > +     if (pdev->vendor == PCI_VENDOR_ID_AMD && pdev->device == 0x15e5)
> > +             xhci->quirks |= XHCI_DISABLE_SPARSE;
> > +
> >        if (pdev->vendor == PCI_VENDOR_ID_AMD)
> >                xhci->quirks |= XHCI_TRUST_TX_LENGTH;
> >
> > @@ -498,6 +503,15 @@ static void xhci_pme_quirk(struct usb_hcd *hcd)
> >        readl(reg);
> >   }
> >
> > +static void xhci_sparse_control_quirk(struct usb_hcd *hcd)
> > +{
> > +     u32 reg;
> > +
> > +     reg = readl(hcd->regs + SPARSE_CNTL_ENABLE);
> > +     reg &= ~BIT(SPARSE_DISABLE_BIT);
> > +     writel(reg, hcd->regs + SPARSE_CNTL_ENABLE);
> > +}
> > +
> >   static int xhci_pci_suspend(struct usb_hcd *hcd, bool do_wakeup)
> >   {
> >        struct xhci_hcd *xhci = hcd_to_xhci(hcd);
> > @@ -517,6 +531,9 @@ static int xhci_pci_suspend(struct usb_hcd *hcd, bool do_wakeup)
> >        if (xhci->quirks & XHCI_SSIC_PORT_UNUSED)
> >                xhci_ssic_port_unused_quirk(hcd, true);
> >
> > +     if (xhci->quirks & XHCI_DISABLE_SPARSE)
> > +             xhci_sparse_control_quirk(hcd);
> > +
> >        ret = xhci_suspend(xhci, do_wakeup);
> >        if (ret && (xhci->quirks & XHCI_SSIC_PORT_UNUSED))
> >                xhci_ssic_port_unused_quirk(hcd, false);
> > --
> > 2.25.1
> Does this build?  There is no XHCI_DISABLE_SPARSE in the kernel tree at
> the moment...

 Sorry i missed adding xhci.h in this patch i will be sending v2 patch.

> greg k-h

Thanks

Sandeep