Re: [PATCH] drm/msm: return early when allocating fbdev fails

[Nathan Chancellor <nathan@kernel.org>]

On Wed, Feb 22, 2023 at 05:09:40PM +0100, Thomas Zimmermann wrote:
> Hi
> 
> Am 22.02.23 um 16:56 schrieb Tom Rix:
> > building with clang and W=1 reports
> > drivers/gpu/drm/msm/msm_fbdev.c:144:6: error: variable 'helper' is used
> >    uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
> >    if (!fbdev)
> >        ^~~~~~
> > 
> > helper is only initialized after fbdev succeeds, so is in a garbage state at
> > the fail: label.  There is nothing to unwinded if fbdev alloaction fails,
> > return NULL.
> > 
> > Fixes: 3fb1f62f80a1 ("drm/fb-helper: Remove drm_fb_helper_unprepare() from drm_fb_helper_fini()")
> > Signed-off-by: Tom Rix <trix@redhat.com>
> 
> Already fixed here: https://lore.kernel.org/dri-devel/08e3340e-b459-0e60-4bba-30716b675e05@suse.de/T/#t

There is also:

../drivers/gpu/drm/omapdrm/omap_fbdev.c:235:6: error: variable 'helper' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
        if (!fbdev)
            ^~~~~~
../drivers/gpu/drm/omapdrm/omap_fbdev.c:259:26: note: uninitialized use occurs here
        drm_fb_helper_unprepare(helper);
                                ^~~~~~
../drivers/gpu/drm/omapdrm/omap_fbdev.c:235:2: note: remove the 'if' if its condition is always false
        if (!fbdev)
        ^~~~~~~~~~~
../drivers/gpu/drm/omapdrm/omap_fbdev.c:228:30: note: initialize the variable 'helper' to silence this warning
        struct drm_fb_helper *helper;
                                    ^
                                     = NULL
1 error generated.

Is the fix the same as the one you have linked above?

Cheers,
Nathan