From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Deucher Subject: Re: [PATCH 1/3] drm/radeon: Disable dma rings for bo moves on r6xx Date: Thu, 11 Jul 2013 16:05:57 -0400 Message-ID: References: <1373571341-3694-1-git-send-email-alexdeucher@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ve0-f181.google.com (mail-ve0-f181.google.com [209.85.128.181]) by gabe.freedesktop.org (Postfix) with ESMTP id 982E8E5DC7 for ; Thu, 11 Jul 2013 13:05:58 -0700 (PDT) Received: by mail-ve0-f181.google.com with SMTP id db10so7451578veb.40 for ; Thu, 11 Jul 2013 13:05:58 -0700 (PDT) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org Errors-To: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org To: Ilija Hadzic Cc: Alex Deucher , dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org On Thu, Jul 11, 2013 at 3:59 PM, Ilija Hadzic wrote: > > Alex, > > Can you please share some details about the nature or symptom of the > "instability". One problem that I have been seeing on my end is that when I > use the DMA ring intensively (by intensively I mean, calling the copy > function every frame), combined with some 3D rendering that causes a lot of > cs_ioctl calls, that I can provoke a corruption of the olist field in > radeon_sa_bo structure, consequently causing an oops in > radeon_sa_bo_try_free(). I have also found that I can suppress the problem > if I add some padding fields at the beginnig of the radeon_sa_bo structure > (essentially moving the olist field down). > > So I speculate that the use of DMA somehow results in corrupting that > structure, but I have not yet done enough experiments to prove or disprove > that theory (so I have not spoke up yet). Also my kernel is full of my own > internal hacks, and I have not yet taken the time to reproduce the problem > with the "stock" kernel. However, after seeing your patch series, I am > wondering if the instability you are referring to may be of the same or > similar nature. Basically using the DMA engine on r6xx seems to lead to hangs on certain chips when the bo copy callback gets triggered a lot (e.g., a web page with lots of images, etc.). Switching back to the 3D engine fixes the issue. R6xx was the first asic family with the async dma engines, so there are likely some hw bugs at play. Unfortunately, the hw guys haven't looked at 6xx in probably 8 years, so I don't hold out much chance of getting to the root of the problem at this point. Alex > > thanks, > > Ilija > > > > On Thu, 11 Jul 2013, alexdeucher@gmail.com wrote: > >> From: Alex Deucher >> >> They still seem to cause instability on some r6xx parts. >> As a follow up, we can switch to using CP DMA for bo >> moves on r6xx as a lighter weight alternative to using >> the 3D engine. >> >> A version of this patch should also go to stable kernels. >> >> Tested-by: J.N. >> Signed-off-by: Alex Deucher >> --- >> drivers/gpu/drm/radeon/radeon_asic.c | 12 ++++++------ >> 1 files changed, 6 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/gpu/drm/radeon/radeon_asic.c >> b/drivers/gpu/drm/radeon/radeon_asic.c >> index 0970774..ea5c52b 100644 >> --- a/drivers/gpu/drm/radeon/radeon_asic.c >> +++ b/drivers/gpu/drm/radeon/radeon_asic.c >> @@ -1026,8 +1026,8 @@ static struct radeon_asic r600_asic = { >> .blit_ring_index = RADEON_RING_TYPE_GFX_INDEX, >> .dma = &r600_copy_dma, >> .dma_ring_index = R600_RING_TYPE_DMA_INDEX, >> - .copy = &r600_copy_dma, >> - .copy_ring_index = R600_RING_TYPE_DMA_INDEX, >> + .copy = &r600_copy_blit, >> + .copy_ring_index = RADEON_RING_TYPE_GFX_INDEX, >> }, >> .surface = { >> .set_reg = r600_set_surface_reg, >> @@ -1119,8 +1119,8 @@ static struct radeon_asic rv6xx_asic = { >> .blit_ring_index = RADEON_RING_TYPE_GFX_INDEX, >> .dma = &r600_copy_dma, >> .dma_ring_index = R600_RING_TYPE_DMA_INDEX, >> - .copy = &r600_copy_dma, >> - .copy_ring_index = R600_RING_TYPE_DMA_INDEX, >> + .copy = &r600_copy_blit, >> + .copy_ring_index = RADEON_RING_TYPE_GFX_INDEX, >> }, >> .surface = { >> .set_reg = r600_set_surface_reg, >> @@ -1229,8 +1229,8 @@ static struct radeon_asic rs780_asic = { >> .blit_ring_index = RADEON_RING_TYPE_GFX_INDEX, >> .dma = &r600_copy_dma, >> .dma_ring_index = R600_RING_TYPE_DMA_INDEX, >> - .copy = &r600_copy_dma, >> - .copy_ring_index = R600_RING_TYPE_DMA_INDEX, >> + .copy = &r600_copy_blit, >> + .copy_ring_index = RADEON_RING_TYPE_GFX_INDEX, >> }, >> .surface = { >> .set_reg = r600_set_surface_reg, >> -- >> 1.7.7.5 >> >> _______________________________________________ >> dri-devel mailing list >> dri-devel@lists.freedesktop.org >> http://lists.freedesktop.org/mailman/listinfo/dri-devel >> >