[PATCH v2 2/4] gpu/radeon: Move 64-bit MSI quirk from arch to driver

[Alex Deucher]

On Wed, Oct 1, 2014 at 8:33 PM, Benjamin Herrenschmidt
<benh at kernel.crashing.org> 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 radeon driver
>
> Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
> CC: <stable at vger.kernel.org>

Reviewed-by: Alex Deucher <alexander.deucher at amd.com>

> ---
>
> v2: This is just adjusted to the new flag name
>
>  arch/powerpc/kernel/pci_64.c            |  1 -
>  drivers/gpu/drm/radeon/radeon_irq_kms.c | 10 ++++++++++
>  2 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c
> index d41a831..5330f6d 100644
> --- a/arch/powerpc/kernel/pci_64.c
> +++ b/arch/powerpc/kernel/pci_64.c
> @@ -271,5 +271,4 @@ static void quirk_radeon_32bit_msi(struct pci_dev *dev)
>  {
>         dev->no_64bit_msi = true;
>  }
> -DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x68f2, quirk_radeon_32bit_msi);
>  DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0xaa68, quirk_radeon_32bit_msi);
> diff --git a/drivers/gpu/drm/radeon/radeon_irq_kms.c b/drivers/gpu/drm/radeon/radeon_irq_kms.c
> index 16807af..e760671 100644
> --- a/drivers/gpu/drm/radeon/radeon_irq_kms.c
> +++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c
> @@ -202,6 +202,16 @@ static bool radeon_msi_ok(struct radeon_device *rdev)
>         if (rdev->flags & RADEON_IS_AGP)
>                 return false;
>
> +       /*
> +        * Older chips have a HW limitation, they can only generate 40 bits
> +        * of address for "64-bit" MSIs which breaks on some platforms, notably
> +        * IBM POWER servers, so we limit them
> +        */
> +       if (rdev->family < CHIP_BONAIRE) {
> +               dev_info(rdev->dev, "radeon: MSI limited to 32-bit\n");
> +               rdev->pdev->no_64bit_msi = true;
> +       }
> +
>         /* force MSI on */
>         if (radeon_msi == 1)
>                 return true;
>
>