[PATCH 3/6] drm/radeon: Writeback endian fixes

Alex Deucher alexdeucher at gmail.com
Wed Jul 13 19:24:15 PDT 2011


On Wed, Jul 13, 2011 at 5:41 PM, Benjamin Herrenschmidt
<benh at kernel.crashing.org> wrote:
> On Wed, 2011-07-13 at 10:42 -0400, Alex Deucher wrote:
>> On Wed, Jul 13, 2011 at 2:28 AM, Benjamin Herrenschmidt
>> <benh at kernel.crashing.org> wrote:
>> > The writeback ring pointer and IH ring pointer are read using le32_to_cpu
>> > so we do not want the chip to byteswap them on big-endian.
>> >
>> > We still want to byteswap the ring itself and the IBs, so we don't touch
>> > that but we remove setting of the byteswap bits in CP_RB_RPTR_ADDR and
>> > IH_CNTL.
>> >
>> > In general, for things like that where we control all the accessors easily,
>> > we are better off doing the swap in SW rather than HW. Paradoxally, it does
>> > keep the code closer to x86 and avoid using poorly tested HW features.
>> >
>> > I also changed the use of RADEON_ to R600_ in a couple of cases to be more
>> > consistent with the surrounding code.
>> >
>> > Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
>>
>> evergreen.c and ni.c will need similar fixes.
>
> evergreen.c -is- fixed in the patch :-) ni.c doesn't seem to set
> swapping on the write back of the ring pointer (can you dbl check ?), it
> only enables swapping on the ring itself which is correct as far as I
> can tell.

You're right.  Looks good.

Alex


>
> Cheers,
> Ben.
>
>> Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
>>
>> > ---
>> >
>> > (resent adding dri-devel to the CC list to hit patchwork)
>> >
>> >  drivers/gpu/drm/radeon/evergreen.c |    3 ---
>> >  drivers/gpu/drm/radeon/r600.c      |    7 -------
>> >  drivers/gpu/drm/radeon/r600_cp.c   |   23 +++++++++--------------
>> >  3 files changed, 9 insertions(+), 24 deletions(-)
>> >
>> > diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
>> > index e8a5ffb..23cf089 100644
>> > --- a/drivers/gpu/drm/radeon/evergreen.c
>> > +++ b/drivers/gpu/drm/radeon/evergreen.c
>> > @@ -1359,9 +1359,6 @@ int evergreen_cp_resume(struct radeon_device *rdev)
>> >
>> >        /* set the wb address wether it's enabled or not */
>> >        WREG32(CP_RB_RPTR_ADDR,
>> > -#ifdef __BIG_ENDIAN
>> > -              RB_RPTR_SWAP(2) |
>> > -#endif
>> >               ((rdev->wb.gpu_addr + RADEON_WB_CP_RPTR_OFFSET) & 0xFFFFFFFC));
>> >        WREG32(CP_RB_RPTR_ADDR_HI, upper_32_bits(rdev->wb.gpu_addr + RADEON_WB_CP_RPTR_OFFSET) & 0xFF);
>> >        WREG32(SCRATCH_ADDR, ((rdev->wb.gpu_addr + RADEON_WB_SCRATCH_OFFSET) >> 8) & 0xFFFFFFFF);
>> > diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
>> > index f79d2cc..3c86b15 100644
>> > --- a/drivers/gpu/drm/radeon/r600.c
>> > +++ b/drivers/gpu/drm/radeon/r600.c
>> > @@ -2212,9 +2212,6 @@ int r600_cp_resume(struct radeon_device *rdev)
>> >
>> >        /* set the wb address whether it's enabled or not */
>> >        WREG32(CP_RB_RPTR_ADDR,
>> > -#ifdef __BIG_ENDIAN
>> > -              RB_RPTR_SWAP(2) |
>> > -#endif
>> >               ((rdev->wb.gpu_addr + RADEON_WB_CP_RPTR_OFFSET) & 0xFFFFFFFC));
>> >        WREG32(CP_RB_RPTR_ADDR_HI, upper_32_bits(rdev->wb.gpu_addr + RADEON_WB_CP_RPTR_OFFSET) & 0xFF);
>> >        WREG32(SCRATCH_ADDR, ((rdev->wb.gpu_addr + RADEON_WB_SCRATCH_OFFSET) >> 8) & 0xFFFFFFFF);
>> > @@ -2993,10 +2990,6 @@ int r600_irq_init(struct radeon_device *rdev)
>> >        /* RPTR_REARM only works if msi's are enabled */
>> >        if (rdev->msi_enabled)
>> >                ih_cntl |= RPTR_REARM;
>> > -
>> > -#ifdef __BIG_ENDIAN
>> > -       ih_cntl |= IH_MC_SWAP(IH_MC_SWAP_32BIT);
>> > -#endif
>> >        WREG32(IH_CNTL, ih_cntl);
>> >
>> >        /* force the active interrupt state to all disabled */
>> > diff --git a/drivers/gpu/drm/radeon/r600_cp.c b/drivers/gpu/drm/radeon/r600_cp.c
>> > index c3ab959..45fd592 100644
>> > --- a/drivers/gpu/drm/radeon/r600_cp.c
>> > +++ b/drivers/gpu/drm/radeon/r600_cp.c
>> > @@ -1802,8 +1802,8 @@ static void r600_cp_init_ring_buffer(struct drm_device *dev,
>> >        /* Set ring buffer size */
>> >  #ifdef __BIG_ENDIAN
>> >        RADEON_WRITE(R600_CP_RB_CNTL,
>> > -                    RADEON_BUF_SWAP_32BIT |
>> > -                    RADEON_RB_NO_UPDATE |
>> > +                    R600_BUF_SWAP_32BIT |
>> > +                    R600_RB_NO_UPDATE |
>> >                     (dev_priv->ring.rptr_update_l2qw << 8) |
>> >                     dev_priv->ring.size_l2qw);
>> >  #else
>> > @@ -1820,15 +1820,15 @@ static void r600_cp_init_ring_buffer(struct drm_device *dev,
>> >
>> >  #ifdef __BIG_ENDIAN
>> >        RADEON_WRITE(R600_CP_RB_CNTL,
>> > -                    RADEON_BUF_SWAP_32BIT |
>> > -                    RADEON_RB_NO_UPDATE |
>> > -                    RADEON_RB_RPTR_WR_ENA |
>> > +                    R600_BUF_SWAP_32BIT |
>> > +                    R600_RB_NO_UPDATE |
>> > +                    R600_RB_RPTR_WR_ENA |
>> >                     (dev_priv->ring.rptr_update_l2qw << 8) |
>> >                     dev_priv->ring.size_l2qw);
>> >  #else
>> >        RADEON_WRITE(R600_CP_RB_CNTL,
>> > -                    RADEON_RB_NO_UPDATE |
>> > -                    RADEON_RB_RPTR_WR_ENA |
>> > +                    R600_RB_NO_UPDATE |
>> > +                    R600_RB_RPTR_WR_ENA |
>> >                     (dev_priv->ring.rptr_update_l2qw << 8) |
>> >                     dev_priv->ring.size_l2qw);
>> >  #endif
>> > @@ -1851,13 +1851,8 @@ static void r600_cp_init_ring_buffer(struct drm_device *dev,
>> >                        - ((unsigned long) dev->sg->virtual)
>> >                        + dev_priv->gart_vm_start;
>> >        }
>> > -       RADEON_WRITE(R600_CP_RB_RPTR_ADDR,
>> > -#ifdef __BIG_ENDIAN
>> > -                    (2 << 0) |
>> > -#endif
>> > -                    (rptr_addr & 0xfffffffc));
>> > -       RADEON_WRITE(R600_CP_RB_RPTR_ADDR_HI,
>> > -                    upper_32_bits(rptr_addr));
>> > +       RADEON_WRITE(R600_CP_RB_RPTR_ADDR, (rptr_addr & 0xfffffffc));
>> > +       RADEON_WRITE(R600_CP_RB_RPTR_ADDR_HI, upper_32_bits(rptr_addr));
>> >
>> >  #ifdef __BIG_ENDIAN
>> >        RADEON_WRITE(R600_CP_RB_CNTL,
>> >
>> >
>> >
>> >
>
>
>


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