[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 06.09.2014 01:49, Mikael Pettersson wrote:
 > > 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?
 > > 
 > > Tested, sorry no joy.  I first reconfirmed the screen corruption with 3.17-rc3.
 > > I then applied this and rebuilt/rebooted, and after a few minutes X had a hickup
 > > (screen went black, came back after a few seconds, but then no cursor or
 > > reaction to mouse events), but I was able to kill it via my Terminate_Server
 > > key binding.
 > 
 > I was afraid so, thanks for testing it.
 > 
 > 
 > I can't see any other option than the patch below then. Can you confirm that this
 > fixes the screen corruption?

It does, thanks.

Tested-by: Mikael Pettersson <mikpelinux at gmail.com>

 > 
 > 
 > diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c
 > index 4c5ec44..b0098e7 100644
 > --- a/drivers/gpu/drm/radeon/r100.c
 > +++ b/drivers/gpu/drm/radeon/r100.c
 > @@ -821,6 +821,20 @@ u32 r100_get_vblank_counter(struct radeon_device *rdev, int crtc)
 >  		return RREG32(RADEON_CRTC2_CRNT_FRAME);
 >  }
 >  
 > +/**
 > + * r100_ring_hdp_flush - flush Host Data Path via the ring buffer
 > + * rdev: radeon device structure
 > + * ring: ring buffer struct for emitting packets
 > + */
 > +static void r100_ring_hdp_flush(struct radeon_device *rdev, struct radeon_ring *ring)
 > +{
 > +	radeon_ring_write(ring, PACKET0(RADEON_HOST_PATH_CNTL, 0));
 > +	radeon_ring_write(ring, rdev->config.r100.hdp_cntl |
 > +				RADEON_HDP_READ_BUFFER_INVALIDATE);
 > +	radeon_ring_write(ring, PACKET0(RADEON_HOST_PATH_CNTL, 0));
 > +	radeon_ring_write(ring, rdev->config.r100.hdp_cntl);
 > +}
 > +
 >  /* Who ever call radeon_fence_emit should call ring_lock and ask
 >   * for enough space (today caller are ib schedule and buffer move) */
 >  void r100_fence_ring_emit(struct radeon_device *rdev,
 > @@ -1056,20 +1070,6 @@ void r100_gfx_set_wptr(struct radeon_device *rdev,
 >  	(void)RREG32(RADEON_CP_RB_WPTR);
 >  }
 >  
 > -/**
 > - * r100_ring_hdp_flush - flush Host Data Path via the ring buffer
 > - * rdev: radeon device structure
 > - * ring: ring buffer struct for emitting packets
 > - */
 > -void r100_ring_hdp_flush(struct radeon_device *rdev, struct radeon_ring *ring)
 > -{
 > -	radeon_ring_write(ring, PACKET0(RADEON_HOST_PATH_CNTL, 0));
 > -	radeon_ring_write(ring, rdev->config.r100.hdp_cntl |
 > -				RADEON_HDP_READ_BUFFER_INVALIDATE);
 > -	radeon_ring_write(ring, PACKET0(RADEON_HOST_PATH_CNTL, 0));
 > -	radeon_ring_write(ring, rdev->config.r100.hdp_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..2dd5847 100644
 > --- a/drivers/gpu/drm/radeon/radeon_asic.c
 > +++ b/drivers/gpu/drm/radeon/radeon_asic.c
 > @@ -185,7 +185,6 @@ static struct radeon_asic_ring r100_gfx_ring = {
 >  	.get_rptr = &r100_gfx_get_rptr,
 >  	.get_wptr = &r100_gfx_get_wptr,
 >  	.set_wptr = &r100_gfx_set_wptr,
 > -	.hdp_flush = &r100_ring_hdp_flush,
 >  };
 >  
 >  static struct radeon_asic r100_asic = {
 > @@ -332,7 +331,6 @@ static struct radeon_asic_ring r300_gfx_ring = {
 >  	.get_rptr = &r100_gfx_get_rptr,
 >  	.get_wptr = &r100_gfx_get_wptr,
 >  	.set_wptr = &r100_gfx_set_wptr,
 > -	.hdp_flush = &r100_ring_hdp_flush,
 >  };
 >  
 >  static struct radeon_asic r300_asic = {
 > diff --git a/drivers/gpu/drm/radeon/radeon_asic.h b/drivers/gpu/drm/radeon/radeon_asic.h
 > index 275a5dc..7756bc1 100644
 > --- a/drivers/gpu/drm/radeon/radeon_asic.h
 > +++ b/drivers/gpu/drm/radeon/radeon_asic.h
 > @@ -148,8 +148,7 @@ u32 r100_gfx_get_wptr(struct radeon_device *rdev,
 >  		      struct radeon_ring *ring);
 >  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);
 > +
 >  /*
 >   * r200,rv250,rs300,rv280
 >   */
 > diff --git a/drivers/gpu/drm/radeon/radeon_drv.c b/drivers/gpu/drm/radeon/radeon_drv.c
 > index a773830..ef5b60a 100644
 > --- a/drivers/gpu/drm/radeon/radeon_drv.c
 > +++ b/drivers/gpu/drm/radeon/radeon_drv.c
 > @@ -83,7 +83,7 @@
 >   *            CIK: 1D and linear tiling modes contain valid PIPE_CONFIG
 >   *   2.39.0 - Add INFO query for number of active CUs
 >   *   2.40.0 - Add RADEON_GEM_GTT_WC/UC, flush HDP cache before submitting
 > - *            CS to GPU
 > + *            CS to GPU on >= r600
 >   */
 >  #define KMS_DRIVER_MAJOR	2
 >  #define KMS_DRIVER_MINOR	40
 > 
 > 
 > 
 > -- 
 > Earthling Michel Dänzer            |                  http://www.amd.com
 > Libre software enthusiast          |                Mesa and X developer

--