<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> </head> <body text="#000000" bgcolor="#FFFFFF"> <div class="moz-cite-prefix">On 2018-06-25 02:53 PM, Alex Deucher wrote: </div> <blockquote type="cite" cite="mid:CADnq5_NVoR3zRRPWdQHTbRzZ7e0XYsjajDSx-jS_sa0-B3id1Q@mail.gmail.com"> <pre wrap="">On Mon, Jun 25, 2018 at 2:37 PM, James Zhu <a class="moz-txt-link-rfc2396E" href="mailto:jamesz@amd.com"><jamesz@amd.com></a> wrote: </pre> <blockquote type="cite"> <pre wrap="">For one UVD instance case,: In function amdgpu_driver_load_kms, all ring->me should be set to zero. adev = kzalloc(sizeof(struct amdgpu_device), GFP_KERNEL); For two UVD instances cases: static void uvd_v7_0_set_ring_funcs(struct amdgpu_device *adev) .. for (i = 0; i < adev->uvd.num_uvd_inst; i++) { adev->uvd.inst[i].ring.me = i; static void uvd_v7_0_set_enc_ring_funcs(struct amdgpu_device *adev) for (j = 0; j < adev->uvd.num_uvd_inst; j++) { adev->uvd.inst[j].ring_enc[i].me = j; uvd_v4_2_early_init in uvd_v4_2.c adev->uvd.num_uvd_inst = 1; uvd_v5_0_early_init in uvd_v5_0.c adev->uvd.num_uvd_inst = 1; uvd_v6_0_early_init in uvd_v6_0.c adev->uvd.num_uvd_inst = 1; uvd_v7_0_early_init in uvd_v7_0.c if (adev->asic_type == CHIP_VEGA20) adev->uvd.num_uvd_inst = UVD7_MAX_HW_INSTANCES_VEGA20;/*2*/ else adev->uvd.num_uvd_inst = 1; I didn't know when ring->me is set to 2. Maybe there is some leakage somewhere. </pre> </blockquote> <pre wrap=""> What about older uvd (4.2, 5.0, 6.0) blocks?</pre> </blockquote> I think the below code will reset adev->uvd.inst[AMDGPU_MAX_UVD_INSTANCES].ring->me and adev->uvd.inst[AMDGPU_MAX_UVD_INSTANCES].ring_enc[AMDGPU_MAX_UVD_ENC_RINGS]->me to zero. for older uvd IP UVD block. <pre wrap="">adev = kzalloc(sizeof(struct amdgpu_device), GFP_KERNEL); Do I understand correctly? James </pre> <blockquote type="cite" cite="mid:CADnq5_NVoR3zRRPWdQHTbRzZ7e0XYsjajDSx-jS_sa0-B3id1Q@mail.gmail.com"> <pre wrap=""> Alex </pre> <blockquote type="cite"> <pre wrap="">Best regards! James zhu On 2018-06-25 01:29 PM, Deucher, Alexander wrote: Odd. The structure should be 0 initialized. Does this patch help? Alex ________________________________ From: Timothy Pearson <a class="moz-txt-link-rfc2396E" href="mailto:tpearson@raptorengineering.com"><tpearson@raptorengineering.com></a> Sent: Monday, June 25, 2018 11:53:12 AM To: Zhu, James Cc: <a class="moz-txt-link-abbreviated" href="mailto:amd-gfx@lists.freedesktop.org">amd-gfx@lists.freedesktop.org</a>; Deucher, Alexander; Zhou, David(ChunMing); Koenig, Christian Subject: Re: [PATCH] Increase AMDGPU_MAX_UVD_INSTANCES to 3 n 06/25/2018 09:46 AM, James Zhu wrote: </pre> <blockquote type="cite"> <pre wrap=""> On 2018-06-23 08:02 PM, Timothy Pearson wrote: </pre> <blockquote type="cite"> <pre wrap="">amdgpu_fence_driver_start_ring() attempts to access UVD instance 2 during setup, while the existing UVD instance count only allows instances 0 and 1. Increase AMDGPU_MAX_UVD_INSTANCES by one to avoid the invalid array access. Caught by UBSAN. </pre> </blockquote> <pre wrap="">Hi Timothy, >From design of view, it is not right to just change AMDGPU_MAX_UVD_INSTANCES to 3. Could you tell me some detail of UBSAN test and attach the dmesg also? </pre> </blockquote> <pre wrap=""> Definitely, was looking for some feedback from anyone knowing more about the internals of the UVD system. What's happening is that "ring->me" in amdgpu_fence_driver_start_ring() (drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c:379) is set to a value of "2". The overall dmesg is otherwise uninteresting, but I can try to grab the UBSAN output if needed. -- Timothy Pearson Raptor Engineering +1 (415) 727-8645 (direct line) +1 (512) 690-0200 (switchboard) <a class="moz-txt-link-freetext" href="https://www.raptorengineering.com">https://www.raptorengineering.com</a> _______________________________________________ amd-gfx mailing list <a class="moz-txt-link-abbreviated" href="mailto:amd-gfx@lists.freedesktop.org">amd-gfx@lists.freedesktop.org</a> <a class="moz-txt-link-freetext" href="https://lists.freedesktop.org/mailman/listinfo/amd-gfx">https://lists.freedesktop.org/mailman/listinfo/amd-gfx</a> </pre> </blockquote> </blockquote> </body> </html>