Re: [PATCH] drm/amdkfd: Ensure consistent barrier state saved in gfx12 trap handler

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Feb 21, 2025 at 06:08:52PM +0000, Lancelot SIX wrote:
> It is possible for some waves in a workgroup to finish their save
> sequence before the group leader has had time to capture the workgroup
> barrier state.  When this happens, having those waves exit do impact the
> barrier state.  As a consequence, the state captured by the group leader
> is invalid, and is eventually incorrectly restored.
> 
> This patch proposes to have all waves in a workgroup wait for each other
> at the end of their save sequence (just before calling s_endpgm_saved).
> 
> This is a cherry-pick.  The cwsr_trap_handler.h part of the original
> part was valid and applied cleanly.  The part of the patch that applied
> to cwsr_trap_handler_gfx12.asm did not apply cleanly since
> 80ae55e6115ef "drm/amdkfd: Move gfx12 trap handler to separate file" is
> not part of this branch.  Instead, I ported the change to
> cwsr_trap_handler_gfx10.asm, and guarded it with "ASIC_FAMILY >=
> CHIP_GFX12".
> 
> Signed-off-by: Lancelot SIX <lancelot.six@amd.com>
> Reviewed-by: Jay Cornwall <jay.cornwall@amd.com>
> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
> Cc: stable@vger.kernel.org # 6.12.x
> (cherry picked from commit d584198a6fe4c51f4aa88ad72f258f8961a0f11c)
> Signed-off-by: Lancelot SIX <lancelot.six@amd.com>
> ---
>  drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler.h         | 3 ++-
>  drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler_gfx10.asm | 6 ++++++
>  2 files changed, 8 insertions(+), 1 deletion(-)

What stable branch is this to be applied to?

thanks,

greg k-h