Re: (subset) linux-next: build failure after merge of the pwm tree

[Lee Jones <lee@kernel.org>]

On Fri, 05 Jan 2024, Stephen Rothwell wrote:

> Hi all,
> 
> On Thu, 4 Jan 2024 12:50:28 +0000 Sean Young <sean@mess.org> wrote:
> >
> > On Thu, Jan 04, 2024 at 05:02:41PM +0700, Bagas Sanjaya wrote:
> > > [also add Jingoo (additional backlight maintainer) and Linus]
> > > 
> > > On Thu, Dec 21, 2023 at 07:34:57PM +0100, Thierry Reding wrote:  
> > > > On Thu, Dec 21, 2023 at 12:58:01PM +0000, Lee Jones wrote:  
> > > > > On Thu, 21 Dec 2023, Lee Jones wrote:
> > > > >   
> > > > > > On Thu, 21 Dec 2023 16:58:05 +1100, Stephen Rothwell wrote:  
> > > > > > > After merging the backlight tree, today's linux-next build (x86_64
> > > > > > > allmodconfig) failed like this:
> > > > > > > 
> > > > > > > drivers/video/backlight/mp3309c.c: In function 'mp3309c_bl_update_status':
> > > > > > > drivers/video/backlight/mp3309c.c:134:23: error: implicit declaration of function 'pwm_apply_state'; did you mean 'pwm_apply_args'? [-Werror=implicit-function-declaration]
> > > > > > >   134 |                 ret = pwm_apply_state(chip->pwmd, &pwmstate);
> > > > > > >       |                       ^~~~~~~~~~~~~~~
> > > > > > >       |                       pwm_apply_args
> > > > > > > 
> > > > > > > [...]  
> > > > > > 
> > > > > > Applied, thanks!
> > > > > > 
> > > > > > [1/1] linux-next: build failure after merge of the pwm tree
> > > > > >       commit: f7baa9ccef93ba1c36a8ecf58c2f4e86fb3181b9  
> > > > > 
> > > > > Actually it's:
> > > > > 
> > > > >   f7baa9ccef93b ("backlight: mp3309c: Rename  pwm_apply_state() to pwm_apply_might_sleep()")
> > > > > 
> > > > > But don't bank on the commit ID staying the same.  
> > > > 
> > > > This is likely going to break the build on your branch because
> > > > pwm_apply_might_sleep() is only available in the PWM tree right now. In
> > > > any case, I've now pushed a commit that adds pwm_apply_state() back as a
> > > > compatibility stub, so it should be okay for you to drop this if you
> > > > run into problems. It's always possible that somebody else wants to add
> > > > a new caller of pwm_apply_state() and in retrospect we should've
> > > > probably done this from the start, at least as a transitional measure
> > > > for one or two cycles.
> > > >   
> > > 
> > > Hi Lee and Thierry,
> > > 
> > > I know that we're still on New Year vibes, so some things are not up to full
> > > steam for now; but since we're close to v6.7 release and v6.8 merge window,
> > > hence allow me to ask:
> > > 
> > > Stephen Rothwell is still complaining about backlight tree build failure
> > > due to f7baa9ccef93b, yet it has not been fixed so far. Has the culprit
> > > been dropped/reverted as he requested? The worst case is the culprit slips
> > > through and become part of backlight PR and Linus will likely not happy
> > > with the build regression (maybe he had to fix by himself).  
> > 
> > This should be fixed by 9a216587a03df, and on current linux-next I can't 
> > reproduce the problem any more (x86_64 allmodconfig).
> 
> Of course linux-next is fine, because I have fixed it up in there.
> 
> Here is the problem:  the backlight tree
> (git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight.git#for-backlight-next)
> is broken when built in its own because of the above patch (which is
> commit f7baa9ccef93).  In linux-next, I have been merging the previous
> working version of the backlight tree (with head commit 7d84a63a39b7).
> The patch (commit f7baa9ccef93) can only be applied to the merge of the
> backlight tree and the pwm tree
> (git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm.git#for-next)
> which is merged much later in the linux-next process.  If the backlight
> tree was merged by Linus before the pwm tree, it would break his build
> (and he would not be happy).  But the patch on the head of the
> backlight tree was made unnecessary by commit 9a216587a03d in the pwm
> tree.  So, please either revert commit f7baa9ccef93 in the backlight
> tree (or simply to a "git reset --hard HEAD^" there).  The patch of
> commit f7baa9ccef93 can be applied some time later (after Linus has
> merged both trees.

Works for me.

It is done!

-- 
Lee Jones [李琼斯]