"Fixes:" tags on commits with Cc: stable

"Fixes:" tags on commits with Cc: stable

[Viktor Jägersküpper]

Hi,

regarding a recent fix for AMDGPU which was tagged with Cc: stable, Greg
wrote that the "Fixes:" tag in that commit was wrong from his point of
view: It referenced a commit which was not contained in the mainline
kernel, but only in the drm-next branch (for the next merge window). The
patch from the referenced commit had been cherry-picked for the mainline
kernel via the drm-fixes branch, so Greg argued that the "Fixes:" tag
should have referenced that commit because a reference to a non-mainline
commit doesn't work with the stable team's tooling, which was confirmed
by Sasha.

However, Alex mentioned that some time ago it was determined that the
"Fixes" tag should reference the original commit (drm-next is upstream
for drm-fixes I guess) so that you could follow the cherry-pick -x chain.

As far as I can tell, the documentation doesn't say explicitly what is
correct. Since this issue might be relevant for more people, I'm asking
for a clarification so that the issue can be avoided in the future. Most
likely the documentation should be made clear on this matter.

Regards,
Viktor

Re: "Fixes:" tags on commits with Cc: stable

[Greg Kroah-Hartman]

On Fri, Aug 14, 2026 at 07:20:57PM +0200, Viktor Jägersküpper wrote:
> Hi,
> 
> regarding a recent fix for AMDGPU which was tagged with Cc: stable, Greg
> wrote that the "Fixes:" tag in that commit was wrong from his point of
> view: It referenced a commit which was not contained in the mainline
> kernel, but only in the drm-next branch (for the next merge window). The
> patch from the referenced commit had been cherry-picked for the mainline
> kernel via the drm-fixes branch, so Greg argued that the "Fixes:" tag
> should have referenced that commit because a reference to a non-mainline
> commit doesn't work with the stable team's tooling, which was confirmed
> by Sasha.
> 
> However, Alex mentioned that some time ago it was determined that the
> "Fixes" tag should reference the original commit (drm-next is upstream
> for drm-fixes I guess) so that you could follow the cherry-pick -x chain.
> 
> As far as I can tell, the documentation doesn't say explicitly what is
> correct. Since this issue might be relevant for more people, I'm asking
> for a clarification so that the issue can be avoided in the future. Most
> likely the documentation should be made clear on this matter.

A Fixes: tag should point to the correct commit that it actually fixes.
When you point to a "future" commit, that just breaks the whole graph
entirely.

Because of this, we know that drm "fixes" are not being applied to
stable kernels properly, which it seems the DRM developers are ok with,
so there's not much more I can say here :(

good luck!

greg k-h