Re: [Intel-gfx] â Fi.CI.BAT: failure for drm/i915/display: Check GGTT to determine phys_base (rev2)

[Andrzej Hajda]

On 07.12.2023 12:26, Andrzej Hajda wrote:
> 
> 
> On 07.12.2023 11:10, Andrzej Hajda wrote:
>> On 07.12.2023 01:18, Patchwork wrote:
>>> *Patch Details*
>>> *Series:*    drm/i915/display: Check GGTT to determine phys_base (rev2)
>>> *URL:*    https://patchwork.freedesktop.org/series/127130/ 
>>> <https://patchwork.freedesktop.org/series/127130/>
>>> *State:*    failure
>>> *Details:* 
>>> https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_127130v2/index.html <https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_127130v2/index.html>
>>>
>>>
>>>   CI Bug Log - changes from CI_DRM_13990 -> Patchwork_127130v2
>>>
>>>
>>>     Summary
>>>
>>> *FAILURE*
>>>
>>> Serious unknown changes coming with Patchwork_127130v2 absolutely 
>>> need to be
>>> verified manually.
>>>
>>> If you think the reported changes have nothing to do with the changes
>>> introduced in Patchwork_127130v2, please notify your bug team 
>>> (I915-ci-infra at lists.freedesktop.org) to allow them
>>> to document this new failure mode, which will reduce false positives 
>>> in CI.
>>>
>>> External URL: 
>>> https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_127130v2/index.html
>>>
>>>
>>>     Participating hosts (37 -> 34)
>>>
>>> Missing (3): fi-pnv-d510 fi-snb-2520m bat-dg1-5
>>>
>>>
>>>     Possible new issues
>>>
>>> Here are the unknown changes that may have been introduced in 
>>> Patchwork_127130v2:
>>>
>>>
>>>       IGT changes
>>>
>>>
>>>         Possible regressions
>>>
>>>   * igt at i915_module_load@load:
>>>       o bat-mtlp-8: PASS
>>> <https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_13990/bat-mtlp-8/igt@i915_module_load@load.html> -> INCOMPLETE <https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_127130v2/bat-mtlp-8/igt@i915_module_load@load.html>
>>
>>
>> It seems related. I think the patch is correct but it just unveils 
>> other display take-over issues.
>> Ie with this patch initial_plane_vma returns valid buffer, but 
>> subsequent display code fails miserably with kernel panic.
>>
>> So until this is not solved, we shouldn't merge the patch, IMO.
>>
>> CC: i915 maintainers and display developers
> 
> 
> After taking a look on panic log [1], I have found:
> [drm:i915_init_ggtt [i915]] Failed to reserve top of GGTT for GuC
> 
> I don't know why it is only debug level? It seems serious failure, as a 
> result i915_init_ggtt fails and probe fails.
> 
> The cause is that initial framebuffer is located at the end of GGTT and 
> it overlaps with reserved area (see ggtt_reserve_guc_top).
> 
> I am not sure how it can be properly fixed, I guess dirty fix could be
> just relocation of vma (hopefully into free area), sth like:
> new_gte = gsm + (ggtt->vm.total - GUC_TOP_RESERVE_SIZE - size) / 
> I915_GTT_PAGE_SIZE;
> memmove(new_gte, gte, size / I915_GTT_PAGE_SIZE);
> 
> but I have no idea of possible side effects :)

I looked once more into the code and maybe you can just pin the buffer 
to earlier address (not overlapping with GuC reservation and current vma 
of the fb):
@@ -143,6 +143,9 @@ initial_plane_vma(struct drm_i915_private *i915,
         if (IS_ERR(vma))
                 goto err_obj;

+       if (base + size > GUC_GGTT_TOP)
+               base = min(base, GUC_GGTT_TOP) - size;
+
         pinctl = PIN_GLOBAL | PIN_OFFSET_FIXED | base;
         if (HAS_GMCH(i915))
                 pinctl |= PIN_MAPPABLE;


Regards
Andrzej

> 
> [1]: 
> https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_127130v2/bat-mtlp-8/pstore0-2849851684_Panic_1.txt
> 
> Regards
> Andrzej
> 
> 
>>
>> Regards
>> Andrzej
>>
>>>
>>>
>>>     Known issues
>>>
>>> Here are the changes found in Patchwork_127130v2 that come from known 
>>> issues:
>>>
>>>
>>>       IGT changes
>>>
>>>
>>>         Issues hit
>>>
>>>   * igt at kms_pm_backlight@basic-brightness at edp-1:
>>>       o bat-rplp-1: NOTRUN -> ABORT
>>> <https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_127130v2/bat-rplp-1/igt@kms_pm_backlight@basic-brightness@edp-1.html> (i915#8668 <https://gitlab.freedesktop.org/drm/intel/issues/8668>)
>>>
>>>
>>>         Possible fixes
>>>
>>>   *
>>>
>>>     igt at gem_exec_suspend@basic-s0 at lmem0:
>>>
>>>       o bat-dg2-9: INCOMPLETE
>>> <https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_13990/bat-dg2-9/igt@gem_exec_suspend@basic-s0@lmem0.html> (i915#9275 <https://gitlab.freedesktop.org/drm/intel/issues/9275>) -> PASS <https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_127130v2/bat-dg2-9/igt@gem_exec_suspend@basic-s0@lmem0.html>
>>>   *
>>>
>>>     igt at kms_flip@basic-flip-vs-dpms at d-dp6:
>>>
>>>       o bat-adlp-11: DMESG-FAIL
>>> <https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_13990/bat-adlp-11/igt@kms_flip@basic-flip-vs-dpms@d-dp6.html> (i915#6868 <https://gitlab.freedesktop.org/drm/intel/issues/6868>) -> PASS <https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_127130v2/bat-adlp-11/igt@kms_flip@basic-flip-vs-dpms@d-dp6.html>
>>>   *
>>>
>>>     igt at kms_flip@basic-flip-vs-modeset at d-dp6:
>>>
>>>       o bat-adlp-11: DMESG-WARN
>>> <https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_13990/bat-adlp-11/igt@kms_flip@basic-flip-vs-modeset@d-dp6.html> -> PASS <https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_127130v2/bat-adlp-11/igt@kms_flip@basic-flip-vs-modeset@d-dp6.html>
>>>   *
>>>
>>>     igt at kms_pipe_crc_basic@read-crc-frame-sequence at pipe-d-edp-1:
>>>
>>>       o bat-rplp-1: ABORT
>>> <https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_13990/bat-rplp-1/igt@kms_pipe_crc_basic@read-crc-frame-sequence@pipe-d-edp-1.html> (i915#8668 <https://gitlab.freedesktop.org/drm/intel/issues/8668>) -> PASS <https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_127130v2/bat-rplp-1/igt@kms_pipe_crc_basic@read-crc-frame-sequence@pipe-d-edp-1.html>
>>>
>>>
>>>     Build changes
>>>
>>>   * Linux: CI_DRM_13990 -> Patchwork_127130v2
>>>
>>> CI-20190529: 20190529
>>> CI_DRM_13990: 85d33d0ad82a5c1a71492f14a5ceb67ada6a22d8 @ 
>>> git://anongit.freedesktop.org/gfx-ci/linux
>>> IGT_7626: 154b7288552cd7ed3033f8ef396e88d0bd1b7646 @ 
>>> https://gitlab.freedesktop.org/drm/igt-gpu-tools.git
>>> Patchwork_127130v2: 85d33d0ad82a5c1a71492f14a5ceb67ada6a22d8 @ 
>>> git://anongit.freedesktop.org/gfx-ci/linux
>>>
>>>
>>>       Linux commits
>>>
>>> 43f210e851cd drm/i915/display: Check GGTT to determine phys_base
>>>
>>