Re: Patch "phy: qcom-qmp-combo: fix runtime suspend" has been added to the 5.15-stable tree

[Johan Hovold <johan@kernel.org>]

On Tue, Dec 27, 2022 at 08:04:11AM -0500, Sasha Levin wrote:
> On Tue, Dec 27, 2022 at 10:14:59AM +0100, Johan Hovold wrote:
> >On Sun, Dec 25, 2022 at 10:09:13AM -0500, Sasha Levin wrote:
> >> This is a note to let you know that I've just added the patch titled
> >>
> >>     phy: qcom-qmp-combo: fix runtime suspend
> >>
> >> to the 5.15-stable tree which can be found at:
> >>     http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
> >>
> >> The filename of the patch is:
> >>      phy-qcom-qmp-combo-fix-runtime-suspend.patch
> >> and it can be found in the queue-5.15 subdirectory.
> >>
> >> If you, or anyone else, feels it should not be added to the stable tree,
> >> please let <stable@vger.kernel.org> know about it.
> >>
> >>
> >>
> >> commit d17b3a7b0119f7d92788acbe0f3d3b31bd8f892b
> >> Author: Johan Hovold <johan+linaro@kernel.org>
> >> Date:   Mon Nov 14 09:13:45 2022 +0100
> >>
> >>     phy: qcom-qmp-combo: fix runtime suspend
> >>
> >>     [ Upstream commit c7b98de745cffdceefc077ad5cf9cda032ef8959 ]
> >>
> >>     Drop the confused runtime-suspend type check which effectively broke
> >>     runtime PM if the DP child node happens to be parsed before the USB
> >>     child node during probe (e.g. due to order of child nodes in the
> >>     devicetree).
> >>
> >>     Instead use the new driver data USB PHY pointer to access the USB
> >>     configuration and resources.
> >>
> >>     Fixes: 52e013d0bffa ("phy: qcom-qmp: Add support for DP in USB3+DP combo phy")
> >>     Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> >>     Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> >>     Link: https://lore.kernel.org/r/20221114081346.5116-6-johan+linaro@kernel.org
> >>     Signed-off-by: Vinod Koul <vkoul@kernel.org>
> >>     Signed-off-by: Sasha Levin <sashal@kernel.org>
> >
> >This one was not marked for stable and can not be backported without
> >further dependencies. This driver did not even exist in 5.15, and no,
> >you should no try to backport the split of the original driver either.
> 
> I'll drop this patch.
> 
> >Sasha, please stop this madness.
> 
> So help me understand this... The fixes tag says:
> 
> 	Fixes: 52e013d0bffa ("phy: qcom-qmp: Add support for DP in USB3+DP combo phy")
> 
> 52e013d0bffa was merged in v5.10. Does the tag point to the wrong
> commit?

The fixes tag is correct, but the qmp driver has since been split into
multiple drivers.

But first, the commit in question will not even compile without
7a7d86d14d07 ("phy: qcom-qmp-combo: fix broken power on") which from
what I can tell has not yet been backported (even though it has a stable
tag).

Did you make sure that you compile-tested this patch after applying it
to 5.15?

Second, this commit fixes the combo driver which did not exist before
94a407cc17a4 (phy: qcom-qmp: create copies of QMP PHY driver) which
split the older driver into multiple drivers. This onef and all the
follow-on cleanups should not be backported.

If we find anything that really needs to be fixed in stable kernels
prior to the driver split, those fixes need to be backported properly
to the older version of the driver. This should not be automated.

Johan