On Sunday 20 December 2009 11:56:44 am Simon Horman wrote: > On Sun, Dec 20, 2009 at 09:03:27AM +0200, Marin Mitov wrote: > > Hello all, > > > > Silancing a false positive: > > warning: 'width' may be used uninitialized in this function > > drivers/gpu/drm/drm_edid.c > > Is it guaranteed that the switch will always see a value covered by the > four cases it has?
Yes it is. The value is masked (& 0xc0) so all the possible values are (0x00, 0x40, 0x80, 0xc0) covered by the switch. That's why it is false positive. > If not width would be used without having been initialised. > > Perhaps adding > > default: > BUG(); > > would be worthwhile? > > > > > Signed-off-by: Marin Mitov <[email protected]> > > ========================================================================== > > --- a/drivers/gpu/drm/drm_edid.c 2009-12-20 07:43:57.000000000 +0200 > > +++ b/drivers/gpu/drm/drm_edid.c 2009-12-20 07:45:49.000000000 +0200 > > @@ -913,7 +913,7 @@ > > const int rates[] = { 60, 85, 75, 60, 50 }; > > > > for (i = 0; i < 4; i++) { > > - int width, height; > > + int uninitialized_var(width), height; > > cvt = &(timing->data.other_data.data.cvt[i]); > > > > height = (cvt->code[0] + ((cvt->code[1] & 0xf0) << 8) + 1) * 2; > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to [email protected] > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/ > ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev -- _______________________________________________ Dri-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/dri-devel
