Re: [PATCH 2/2] fbdev: ssd1307fb: check return value while setting offset

From: Maxime Ripard
Date: Tue Jan 13 2015 - 08:40:14 EST


On Tue, Jan 13, 2015 at 11:53:01AM +0000, Prabhakar Lad wrote:
> On Tue, Jan 13, 2015 at 11:43 AM, Tomi Valkeinen <tomi.valkeinen@xxxxxx> wrote:
> > On 08/01/15 10:17, Lad, Prabhakar wrote:
> >> this patch checks the return value of write command while
> >> setting the display offset.
> >>
> >> Signed-off-by: Lad, Prabhakar <prabhakar.csengg@xxxxxxxxx>
> >> ---
> >> drivers/video/fbdev/ssd1307fb.c | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
> >> index 70e3ce8..a7ecaa6 100644
> >> --- a/drivers/video/fbdev/ssd1307fb.c
> >> +++ b/drivers/video/fbdev/ssd1307fb.c
> >> @@ -342,7 +342,7 @@ static int ssd1307fb_ssd1306_init(struct ssd1307fb_par *par)
> >>
> >> /* set display offset value */
> >> ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_DISPLAY_OFFSET);
> >> - ret = ssd1307fb_write_cmd(par->client, 0x20);
> >> + ret = ret & ssd1307fb_write_cmd(par->client, 0x20);
> >> if (ret < 0)
> >> return ret;
> >
> > Hrm, what's that supposed to do? If both calls to ssd1307fb_write_cmd()
> > return an error, they are anded, resulting in a garbage error code...
> >
> Agreed I have just aligned this to rest of the code in this function.
>
> Maxime if you are OK I'll post a patch returning error then and there ?

I'm not sure what the question is, but Tomi is right, having two
returns seems the right thing to do.

Maxime

--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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