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

- From: Prabhakar Lad \<prabhakar.csengg@gmail.com\>
- Date: 2015-01-13 13:46:45 
- List: linux-fbdev
- Page: https://ratatoskr.run/linux-fbdev/2015/01/4408748
- Thread: https://ratatoskr.run/linux-fbdev/2015/01/4405334/t.md

```text
On Tue, Jan 13, 2015 at 1:39 PM, Maxime Ripard
[ref] wrote:
> On Tue, Jan 13, 2015 at 11:53:01AM +0000, Prabhakar Lad wrote:
>> On Tue, Jan 13, 2015 at 11:43 AM, Tomi Valkeinen [ref] 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@gmail.com>
>> >> ---
>> >>  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.
>
OK I'll post a new patch having two separate returns.

Thanks,
--Prabhakar Lad
```