On Thu, Jul 11, 2013 at 09:35:17PM +0100, Damien Lespiau wrote: > On Thu, Jul 11, 2013 at 09:52:33PM +0200, Daniel Vetter wrote: > > On Thu, Jul 11, 2013 at 07:46:00PM +0100, Damien Lespiau wrote: > > > If intel_sdvo_get_value() fails here, val is unitialized and the cross > > > check won't check anything. > > > > > > Signed-off-by: Damien Lespiau <damien.lespiau at intel.com> > > > --- > > > drivers/gpu/drm/i915/intel_sdvo.c | 5 ++++- > > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c > > > index b8e1623..4481f6a 100644 > > > --- a/drivers/gpu/drm/i915/intel_sdvo.c > > > +++ b/drivers/gpu/drm/i915/intel_sdvo.c > > > @@ -1357,7 +1357,10 @@ static void intel_sdvo_get_config(struct intel_encoder *encoder, > > > } > > > > > > /* Cross check the port pixel multiplier with the sdvo encoder state. */ > > > - intel_sdvo_get_value(intel_sdvo, SDVO_CMD_GET_CLOCK_RATE_MULT, &val, 1); > > > + if (!intel_sdvo_get_value(intel_sdvo, SDVO_CMD_GET_CLOCK_RATE_MULT, > > > + &val, 1)) > > > + return; > > > > But now it fails silently instead of being paranoid ... Can we just shut > > up the tool instead? > > We absolutely can! (and it's done). On second thought we could shovel the switch into an if block so that val is only read when written. Since pixel_multiplier is already set to 0 (in case the sdvo device returns garbage) we'll correctly WARN even when get_value fails (and per chance the stack garbage in val is the right value for the pixel multiplier). -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch
