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

On Tue, Jan 13, 2015 at 1:39 PM, Maxime Ripard
[off-list ref] wrote:

On Tue, Jan 13, 2015 at 11:53:01AM +0000, Prabhakar Lad wrote:

quoted

On Tue, Jan 13, 2015 at 11:43 AM, Tomi Valkeinen [off-list ref] wrote:

quoted

On 08/01/15 10:17, Lad, Prabhakar wrote:

quoted

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