linux-kernel - Re: [PATCH v1 1/1] platform/x86: ideapad-laptop: Make the scope

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Message-ID: <ZtjAmavK5tr4mvka@surfacebook.localdomain>
Date: Wed, 4 Sep 2024 23:18:33 +0300
From: Andy Shevchenko <andy.shevchenko@...il.com>
To: Hans de Goede <hdegoede@...hat.com>
Cc: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
	Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
	Gergo Koteles <soyer@....hu>, platform-driver-x86@...r.kernel.org,
	linux-kernel@...r.kernel.org, Ike Panhc <ike.pan@...onical.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Josh Poimboeuf <jpoimboe@...nel.org>,
	Nathan Chancellor <nathan@...nel.org>,
	kernel test robot <lkp@...el.com>
Subject: Re: [PATCH v1 1/1] platform/x86: ideapad-laptop: Make the
 scope_guard() clear of its scope

Wed, Sep 04, 2024 at 08:14:53PM +0200, Hans de Goede kirjoitti:
> Hi,
> 
> On 8/29/24 6:50 PM, Andy Shevchenko wrote:
> > First of all, it's a bit counterintuitive to have something like
> > 
> > 	int err;
> > 	...
> > 	scoped_guard(...)
> > 		err = foo(...);
> > 	if (err)
> > 		return err;
> > 
> > Second, with a particular kernel configuration and compiler version in
> > one of such cases the objtool is not happy:
> > 
> >   ideapad-laptop.o: warning: objtool: .text.fan_mode_show: unexpected end of section
> > 
> > I'm not an expert on all this, but the theory is that compiler and
> > linker in this case can't understand that 'result' variable will be
> > always initialized as long as no error has been returned. Assigning
> > 'result' to a dummy value helps with this. Note, that fixing the
> > scoped_guard() scope (as per above) does not make issue gone.
> > 
> > That said, assign dummy value and make the scope_guard() clear of its scope.
> > For the sake of consistency do it in the entire file.
> > 
> > Fixes: 7cc06e729460 ("platform/x86: ideapad-laptop: add a mutex to synchronize VPC commands")
> > Reported-by: kernel test robot <lkp@...el.com>
> > Closes: https://lore.kernel.org/oe-kbuild-all/202408290219.BrPO8twi-lkp@intel.com/
> > Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>

> Thank you for your patch, I've applied this patch to my review-hans 
> branch:
> https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans

Have you had a chance to go through the discussion?

TL;DR: please defer this. There is still no clear understanding of the root
cause and the culprit.

-- 
With Best Regards,
Andy Shevchenko