Subject: Re: [PATCH v2 3/4] sound/radeon: Move 64-bit MSI quirk from arch to driver

From: Takashi Iwai <[email-masked]>
Date: Thu, 02 Oct 2014 09:59:40 +0200

At Wed, 1 Oct 2014 22:13:38 -0400,
Alex Deucher wrote:
> 
> On Wed, Oct 1, 2014 at 8:34 PM, Benjamin Herrenschmidt
> <[email-masked]> wrote:
> >
> > A number of radeon cards have a HW limitation causing them to be
> > unable to generate the full 64-bit of address bits for MSIs. This
> > breaks MSIs on some platforms such as POWER machines.
> >
> > We used to have a powerpc specific quirk to address that on a
> > single card, but this doesn't scale very well, this is better
> > put under control of the drivers who know precisely what a given
> > HW revision can do.
> >
> > This moves the setting of the quirk flag to the audio driver.
> >
> > While recent ASICs have that problem fixed, they don't seem to
> > be listed in the PCI IDs of the current driver, so let's quirk all
> > the ATI HDMI for now. The consequences are nil on x86 anyway.
> >
> > Signed-off-by: Benjamin Herrenschmidt <[email-masked]>
> > CC: <[email-masked]>
> 
> The attached updated patch only flags the affected asics.

Alex's patch looks more comprehensive.  For either patch,

Reviewed-by: Takashi Iwai <[email-masked]>

thanks,

Takashi

> 
> Alex
> 
> > ---
> >  arch/powerpc/kernel/pci_64.c |  6 ------
> >  sound/pci/hda/hda_intel.c    | 10 ++++++++--
> >  sound/pci/hda/hda_priv.h     |  1 +
> >  3 files changed, 9 insertions(+), 8 deletions(-)
> >
> > diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c
> > index 5330f6d..b15194e 100644
> > --- a/arch/powerpc/kernel/pci_64.c
> > +++ b/arch/powerpc/kernel/pci_64.c
> > @@ -266,9 +266,3 @@ int pcibus_to_node(struct pci_bus *bus)
> >  }
> >  EXPORT_SYMBOL(pcibus_to_node);
> >  #endif
> > -
> > -static void quirk_radeon_32bit_msi(struct pci_dev *dev)
> > -{
> > -       dev->no_64bit_msi = true;
> > -}
> > -DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0xaa68, quirk_radeon_32bit_msi);
> > diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
> > index aa302fb..f91ba7f 100644
> > --- a/sound/pci/hda/hda_intel.c
> > +++ b/sound/pci/hda/hda_intel.c
> > @@ -296,7 +296,8 @@ enum {
> >
> >  /* quirks for ATI/AMD HDMI */
> >  #define AZX_DCAPS_PRESET_ATI_HDMI \
> > -       (AZX_DCAPS_NO_TCSEL | AZX_DCAPS_SYNC_WRITE | AZX_DCAPS_POSFIX_LPIB)
> > +       (AZX_DCAPS_NO_TCSEL | AZX_DCAPS_SYNC_WRITE | AZX_DCAPS_POSFIX_LPIB|\
> > +        AZX_DCAPS_NO_MSI64)
> >
> >  /* quirks for Nvidia */
> >  #define AZX_DCAPS_PRESET_NVIDIA \
> > @@ -1505,9 +1506,14 @@ static int azx_first_init(struct azx *chip)
> >                 return -ENXIO;
> >         }
> >
> > -       if (chip->msi)
> > +       if (chip->msi) {
> > +               if (chip->driver_caps & AZX_DCAPS_NO_MSI64) {
> > +                       dev_dbg(card->dev, "Disabling 64bit MSI\n");
> > +                       pci->no_64bit_msi = true;
> > +               }
> >                 if (pci_enable_msi(pci) < 0)
> >                         chip->msi = 0;
> > +       }
> >
> >         if (azx_acquire_irq(chip, 0) < 0)
> >                 return -EBUSY;
> > diff --git a/sound/pci/hda/hda_priv.h b/sound/pci/hda/hda_priv.h
> > index 949cd43..5016014 100644
> > --- a/sound/pci/hda/hda_priv.h
> > +++ b/sound/pci/hda/hda_priv.h
> > @@ -171,6 +171,7 @@ enum { SDI0, SDI1, SDI2, SDI3, SDO0, SDO1, SDO2, SDO3 };
> >  #define AZX_DCAPS_PM_RUNTIME   (1 << 26)       /* runtime PM support */
> >  #define AZX_DCAPS_I915_POWERWELL (1 << 27)     /* HSW i915 powerwell support */
> >  #define AZX_DCAPS_CORBRP_SELF_CLEAR (1 << 28)  /* CORBRP clears itself after reset */
> > +#define AZX_DCAPS_NO_MSI64      (1 << 29)      /* Stick to 32-bit MSIs */
> >
> >  /* HD Audio class code */
> >  #define PCI_CLASS_MULTIMEDIA_HD_AUDIO  0x0403
> >
> >
> >
> >