On Tue, Jul 19, 2022 at 2:57 PM Alex Deucher <alexander.deucher@xxxxxxx> wrote:
>
> The new vkms virtual display code is atomic so there is
> no need to call drm_helper_disable_unused_functions()
> when it is enabled. Doing so can result in a segfault.
> When the driver switched from the old virtual display code
> to the new atomic virtual display code, it was missed that
> we enable virtual display unconditionally under SR-IOV
> so the checks here missed that case. Add the missing
> check for SR-IOV.
>
> There is no equivalent of this patch for Linus' tree
> because the relevant code no longer exists. This patch
> is only relevant to kernels 5.15 and 5.16.
>
> Fixes: 84ec374bd580 ("drm/amdgpu: create amdgpu_vkms (v4)")
> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx # 5.15.x
> Cc: hgoffin@xxxxxxxxxx
Hi Greg,
Is there any chance this can get applied? It fixes a regression on
5.15 and 5.16.
Thanks,
Alex
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_fb.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fb.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fb.c
> index cd0acbea75da..d58ab9deb028 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fb.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fb.c
> @@ -341,7 +341,8 @@ int amdgpu_fbdev_init(struct amdgpu_device *adev)
> }
>
> /* disable all the possible outputs/crtcs before entering KMS mode */
> - if (!amdgpu_device_has_dc_support(adev) && !amdgpu_virtual_display)
> + if (!amdgpu_device_has_dc_support(adev) && !amdgpu_virtual_display &&
> + !amdgpu_sriov_vf(adev))
> drm_helper_disable_unused_functions(adev_to_drm(adev));
>
> drm_fb_helper_initial_config(&rfbdev->helper, bpp_sel);
> --
> 2.35.3
>
