Em Fri, 05 Jun 2015 17:10:53 +0200
Hans Verkuil <hverkuil@xxxxxxxxx> escreveu:
> On 06/05/2015 12:29 PM, Mauro Carvalho Chehab wrote:
> > Remove the following compilation warnings:
> >
> > drivers/media/platform/vivid/vivid-tpg.c: In function 'tpg_gen_text':
> > drivers/media/platform/vivid/vivid-tpg.c:1562:1: warning: the frame size of 1308 bytes is larger than 1024 bytes [-Wframe-larger-than=]
> > }
> > ^
> >
> > This seems to be due to some bad optimization done by gcc.
> >
> > Moving the for() loop to happen inside the macro solves the
> > issue.
> >
> > While here, fix CodingStyle at the switch().
> >
> > Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
> >
> > diff --git a/drivers/media/platform/vivid/vivid-tpg.c b/drivers/media/platform/vivid/vivid-tpg.c
> > index b1147f2df26c..7a3ed580626a 100644
> > --- a/drivers/media/platform/vivid/vivid-tpg.c
> > +++ b/drivers/media/platform/vivid/vivid-tpg.c
> > @@ -1492,12 +1492,10 @@ void tpg_gen_text(const struct tpg_data *tpg, u8 *basep[TPG_MAX_PLANES][2],
> > else if (tpg->field == V4L2_FIELD_SEQ_TB || tpg->field == V4L2_FIELD_SEQ_BT)
> > div = 2;
> >
> > - for (p = 0; p < tpg->planes; p++) {
> > - unsigned vdiv = tpg->vdownsampling[p];
> > - unsigned hdiv = tpg->hdownsampling[p];
> > -
> > - /* Print text */
> > -#define PRINTSTR(PIXTYPE) do { \
> > + /* Print text */
> > +#define PRINTSTR(PIXTYPE) for (p = 0; p < tpg->planes; p++) { \
> > + unsigned vdiv = tpg->vdownsampling[p]; \
> > + unsigned hdiv = tpg->hdownsampling[p]; \
> > PIXTYPE fg; \
> > PIXTYPE bg; \
> > memcpy(&fg, tpg->textfg[p], sizeof(PIXTYPE)); \
> > @@ -1548,16 +1546,19 @@ void tpg_gen_text(const struct tpg_data *tpg, u8 *basep[TPG_MAX_PLANES][2],
> > } \
> > } while (0)
> >
> > - switch (tpg->twopixelsize[p]) {
> > - case 2:
> > - PRINTSTR(u8); break;
> > - case 4:
> > - PRINTSTR(u16); break;
> > - case 6:
> > - PRINTSTR(x24); break;
> > - case 8:
> > - PRINTSTR(u32); break;
> > - }
> > + switch (tpg->twopixelsize[p]) {
>
> This doesn't work I just discovered. Compiling gives this warning:
>
> drivers/media/platform/vivid/vivid-tpg.c: In function ‘tpg_gen_text’:
> drivers/media/platform/vivid/vivid-tpg.c:1549:27: warning: ‘p’ may be used uninitialized in this function [-Wmaybe-uninitialized]
> switch (tpg->twopixelsize[p]) {
> ^
>
Weird. here (gcc 5.1.1) I didn't get any warning.
> And the value for tpg->twopixelsize[p] will actually differ depending on the value of p.
>
> It's probably best to revert this patch.
>
> The correct approach is likely to make four functions, one for case,
> with the macro as the function body.
I tried that (without the for). The result was worse.
I'll double check it latter today.
>
> Regards,
>
> Hans
>
> > + case 2:
> > + PRINTSTR(u8);
> > + break;
> > + case 4:
> > + PRINTSTR(u16);
> > + break;
> > + case 6:
> > + PRINTSTR(x24);
> > + break;
> > + case 8:
> > + PRINTSTR(u32);
> > + break;
> > }
> > }
> >
> >
>
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