Messages in this thread | | | From | Geert Uytterhoeven <> | Date | Mon, 19 Feb 2018 19:40:40 +0100 | Subject | Re: [PATCH 3/3] auxdisplay: img-ascii-lcd: Silence 2 uninitialized warnings |
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Hi Miguel,
On Mon, Feb 19, 2018 at 5:09 PM, Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> wrote: > The warnings are: > > drivers/auxdisplay/img-ascii-lcd.c: warning: 'err' may be used > uninitialized in this function [-Wuninitialized] > > At lines 109 and 207. Reported by Geert using the build service > several times, e.g.: > > https://lkml.org/lkml/2018/2/19/303 > > They are two false positives, since num_chars > 0 in the three present > configurations (boston, malta, sead3). Initializing to an error state by > default silences the warning and makes the code print an error in case a > num_chars == 0 happens in the future (unlikely, since it does not make > sense currently). > > The warnings seem to disappear starting with gcc >= 4.9 > > Cc: Geert Uytterhoeven <geert@linux-m68k.org> > Cc: Paul Burton <paul.burton@mips.com> > Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Thanks for your patch!
I would initialize err to zero, though, as there is no real error condition if called with num_char == 0.
> --- > I will queue it up for 4.17. > > drivers/auxdisplay/img-ascii-lcd.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/auxdisplay/img-ascii-lcd.c b/drivers/auxdisplay/img-ascii-lcd.c > index d8133024fd5d..bd5ebb5c516c 100644 > --- a/drivers/auxdisplay/img-ascii-lcd.c > +++ b/drivers/auxdisplay/img-ascii-lcd.c > @@ -97,7 +97,7 @@ static struct img_ascii_lcd_config boston_config = { > static void malta_update(struct img_ascii_lcd_ctx *ctx) > { > unsigned int i; > - int err; > + int err = 1; > > for (i = 0; i < ctx->cfg->num_chars; i++) { > err = regmap_write(ctx->regmap, > @@ -180,7 +180,7 @@ static int sead3_wait_lcd_idle(struct img_ascii_lcd_ctx *ctx) > static void sead3_update(struct img_ascii_lcd_ctx *ctx) > { > unsigned int i; > - int err; > + int err = 1; > > for (i = 0; i < ctx->cfg->num_chars; i++) { > err = sead3_wait_lcd_idle(ctx);
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
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