WB _init should clear this buffer in very early stage, so it should output 0 if for BARE-METAL or no preemption occurred -----Original Message----- From: amd-gfx [mailto:amd-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx] On Behalf Of Christian K?nig Sent: 2017å¹´10æ??13æ?¥ 17:10 To: Ding, Pixel <Pixel.Ding at amd.com>; amd-gfx at lists.freedesktop.org Cc: Li, Bingley <Bingley.Li at amd.com> Subject: Re: [PATCH 3/4] drm/amdgpu: report preemption fence via amdgpu_fence_info Hi Pixel, > My understanding is that CP will write seqno back to preempted fence offset when preemption occurred. That is correct. But my question is why you want to print a different value here: > + seq_printf(m, "Last preempted 0x%08x\n", > + le32_to_cpu(*(ring->fence_drv.cpu_addr + 2))); That code prints two dw after the address where the CPU writes the seqno. Where is the code which setups the CP to do this? As far as I can see that line should always print just zero (or some random number if the memory is actually not initialized to anything). Regards, Christian. Am 13.10.2017 um 11:03 schrieb Ding, Pixel: > My understanding is that CP will write seqno back to preempted fence offset when preemption occurred. Then if there is a value here we can generally know packet with which fence is preempted. Should driver handle any other thing for this? > > > > > > > > â?? > Sincerely Yours, > Pixel > > > > > > > > On 13/10/2017, 4:51 PM, "Koenig, Christian" <Christian.Koenig at amd.com> wrote: > >>> Is it OK to limit this information only for SRIOV VF on Tonga and Vega whose format is known? It can help use to identify if MCBP is working correctly or not. >> The question is where is this code for Tonga and Vega? I can't find a >> reference to fence_offs in the GFX8 nor GFX9 code we have in >> amd-staging-drm-next. >> >> And if it doesn't depend on the fence_offs in the ring printing it >> like this is just pure speculation. >> >> Regards, >> Christian. >> >> Am 13.10.2017 um 10:41 schrieb Ding, Pixel: >>> Thanks Christian, >>> >>> Iâ??m not sure if I get your point, but yes the preemption fence offset could be changed. >>> >>> Is it OK to limit this information only for SRIOV VF on Tonga and Vega whose format is known? It can help use to identify if MCBP is working correctly or not. >>> >>> >>> â?? >>> Sincerely Yours, >>> Pixel >>> >>> >>> >>> >>> >>> >>> >>> On 13/10/2017, 4:34 PM, "Christian König" <ckoenig.leichtzumerken at gmail.com> wrote: >>> >>>> Am 13.10.2017 um 10:26 schrieb Pixel Ding: >>>>> From: pding <Pixel.Ding at amd.com> >>>>> >>>>> Only report fence for GFX ring. This can help checking MCBP feature. >>>>> >>>>> Signed-off-by: pding <Pixel.Ding at amd.com> >>>>> --- >>>>> drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 7 +++++++ >>>>> 1 file changed, 7 insertions(+) >>>>> >>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c >>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c >>>>> index 09d5a5c..2044758 100644 >>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c >>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c >>>>> @@ -645,6 +645,13 @@ static int amdgpu_debugfs_fence_info(struct seq_file *m, void *data) >>>>> atomic_read(&ring->fence_drv.last_seq)); >>>>> seq_printf(m, "Last emitted 0x%08x\n", >>>>> ring->fence_drv.sync_seq); >>>>> + >>>>> + if (ring->funcs->type != AMDGPU_RING_TYPE_GFX) >>>>> + break; >>>> That should probably be "continue" instead of break, or otherwise >>>> you don't print the other fences any more. >>>> >>>>> + >>>>> + seq_printf(m, "Last preempted 0x%08x\n", >>>>> + le32_to_cpu(*(ring->fence_drv.cpu_addr + 2))); >>>> Is the code to put the preemption fence there already upstream? >>>> >>>> If yes do we really do this like that for all supported generations? >>>> >>>> Regards, >>>> Christian. >>>> >>>>> + >>>>> } >>>>> return 0; >>>>> } _______________________________________________ amd-gfx mailing list amd-gfx at lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx
