[BISECTED] 3.17-rc1 radeon screen corruption due to "Always flush the HDP cache before submitting a CS to the GPU"

[Mikael Pettersson]

Michel Dänzer writes:
 > On 30.08.2014 22:59, Mikael Pettersson wrote:
 > > Since 3.17-rc1 my radeon card (RV370 / X1050 card) causes screen corruption
 > > after a while in X + firefox.  This still occurs with yesterday's HEAD
 > > of Linus' repo.  3.16 and ealier kernels are fine.
 > > 
 > > I ran a bisect, which identified:
 > > 
 > > commit 72a9987edcedb89db988079a03c9b9c65b6ec9ac
 > > Author: Michel Dänzer <michel.daenzer at amd.com>
 > > Date:   Thu Jul 31 18:43:49 2014 +0900
 > > 
 > >      drm/radeon: Always flush the HDP cache before submitting a CS to the GPU
 > > 
 > > as the cause of my screen corruption.  Reverting this from 3.17-rc2
 > > (which requires manual intervention due to subsequent changes in
 > > radeon_ring_commit()) eliminates the screen corruption.
 > 
 > Does the patch below help?

Thanks for the patch, I'll test it on Friday evening when I'm
back home and have access to the affected machine.


 > 
 > diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c
 > index 4c5ec44..3ff9c53 100644
 > --- a/drivers/gpu/drm/radeon/r100.c
 > +++ b/drivers/gpu/drm/radeon/r100.c
 > @@ -1070,6 +1070,20 @@ void r100_ring_hdp_flush(struct radeon_device *rdev, struct radeon_ring *ring)
 >  	radeon_ring_write(ring, rdev->config.r100.hdp_cntl);
 >  }
 >  
 > +/**
 > + * r100_mmio_hdp_flush - flush Host Data Path via MMIO
 > + * rdev: radeon device structure
 > + */
 > +void r100_mmio_hdp_flush(struct radeon_device *rdev)
 > +{
 > +	WREG32(RADEON_HOST_PATH_CNTL,
 > +	       rdev->config.r100.hdp_cntl | RADEON_HDP_READ_BUFFER_INVALIDATE);
 > +	(void)RREG32(RADEON_HOST_PATH_CNTL);
 > +	WREG32(RADEON_HOST_PATH_CNTL,
 > +	       rdev->config.r100.hdp_cntl);
 > +	(void)RREG32(RADEON_HOST_PATH_CNTL);
 > +}
 > +
 >  static void r100_cp_load_microcode(struct radeon_device *rdev)
 >  {
 >  	const __be32 *fw_data;
 > diff --git a/drivers/gpu/drm/radeon/radeon_asic.c b/drivers/gpu/drm/radeon/radeon_asic.c
 > index eeeeabe..c23a123 100644
 > --- a/drivers/gpu/drm/radeon/radeon_asic.c
 > +++ b/drivers/gpu/drm/radeon/radeon_asic.c
 > @@ -408,7 +408,7 @@ static struct radeon_asic r300_asic_pcie = {
 >  	.resume = &r300_resume,
 >  	.vga_set_state = &r100_vga_set_state,
 >  	.asic_reset = &r300_asic_reset,
 > -	.mmio_hdp_flush = NULL,
 > +	.mmio_hdp_flush = r100_mmio_hdp_flush,
 >  	.gui_idle = &r100_gui_idle,
 >  	.mc_wait_for_idle = &r300_mc_wait_for_idle,
 >  	.gart = {
 > diff --git a/drivers/gpu/drm/radeon/radeon_asic.h b/drivers/gpu/drm/radeon/radeon_asic.h
 > index 275a5dc..e9b1c35 100644
 > --- a/drivers/gpu/drm/radeon/radeon_asic.h
 > +++ b/drivers/gpu/drm/radeon/radeon_asic.h
 > @@ -150,6 +150,8 @@ void r100_gfx_set_wptr(struct radeon_device *rdev,
 >  		       struct radeon_ring *ring);
 >  void r100_ring_hdp_flush(struct radeon_device *rdev,
 >  			 struct radeon_ring *ring);
 > +void r100_mmio_hdp_flush(struct radeon_device *rdev);
 > +
 >  /*
 >   * r200,rv250,rs300,rv280
 >   */
 > diff --git a/drivers/gpu/drm/radeon/radeon_gem.c b/drivers/gpu/drm/radeon/radeon_gem.c
 > index bfd7e1b..3d0f564 100644
 > --- a/drivers/gpu/drm/radeon/radeon_gem.c
 > +++ b/drivers/gpu/drm/radeon/radeon_gem.c
 > @@ -368,6 +368,7 @@ int radeon_gem_wait_idle_ioctl(struct drm_device *dev, void *data,
 >  	r = radeon_bo_wait(robj, &cur_placement, false);
 >  	/* Flush HDP cache via MMIO if necessary */
 >  	if (rdev->asic->mmio_hdp_flush &&
 > +	    !rdev->asic->ring[RADEON_RING_TYPE_GFX_INDEX]->hdp_flush &&
 >  	    radeon_mem_type_to_domain(cur_placement) == RADEON_GEM_DOMAIN_VRAM)
 >  		robj->rdev->asic->mmio_hdp_flush(rdev);
 >  	drm_gem_object_unreference_unlocked(gobj);
 > diff --git a/drivers/gpu/drm/radeon/radeon_ring.c b/drivers/gpu/drm/radeon/radeon_ring.c
 > index d656079..b82843b 100644
 > --- a/drivers/gpu/drm/radeon/radeon_ring.c
 > +++ b/drivers/gpu/drm/radeon/radeon_ring.c
 > @@ -188,7 +188,8 @@ void radeon_ring_commit(struct radeon_device *rdev, struct radeon_ring *ring,
 >  	/* If we are emitting the HDP flush via the ring buffer, we need to
 >  	 * do it before padding.
 >  	 */
 > -	if (hdp_flush && rdev->asic->ring[ring->idx]->hdp_flush)
 > +	if (hdp_flush && rdev->asic->ring[ring->idx]->hdp_flush &&
 > +	    !rdev->asic->mmio_hdp_flush)
 >  		rdev->asic->ring[ring->idx]->hdp_flush(rdev, ring);
 >  	/* We pad to match fetch size */
 >  	while (ring->wptr & ring->align_mask) {
 > 
 > 
 > 
 > -- 
 > Earthling Michel Dänzer            |                  http://www.amd.com
 > Libre software enthusiast          |                Mesa and X developer

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