[PATCH] i2c: sh_mobile: Fix compilation warning

[PATCH] i2c: sh_mobile: Fix compilation warning

[Viresh Kumar]

This currently generates a warning:

drivers/i2c/busses/i2c-sh_mobile.c: In function 'sh_mobile_i2c_isr':
drivers/i2c/busses/i2c-sh_mobile.c:399:26: warning: 'data' may be used uninitialized in this function [-Wmaybe-uninitialized]

Though the code looks okay and shouldn't ever use the variable
uninitialized.

Fix the warning by moving the code around and getting rid of 'data'.

Compile tested only.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/i2c/busses/i2c-sh_mobile.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index 8777af4c695e..945eb8504fb7 100644
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -369,7 +369,6 @@ static int sh_mobile_i2c_isr_tx(struct sh_mobile_i2c_data *pd)
 
 static int sh_mobile_i2c_isr_rx(struct sh_mobile_i2c_data *pd)
 {
-	unsigned char data;
 	int real_pos;
 
 	/* switch from TX (address) to RX (data) adds two interrupts */
@@ -390,13 +389,11 @@ static int sh_mobile_i2c_isr_rx(struct sh_mobile_i2c_data *pd)
 		if (real_pos < 0)
 			i2c_op(pd, OP_RX_STOP);
 		else
-			data = i2c_op(pd, OP_RX_STOP_DATA);
+			pd->msg->buf[real_pos] = i2c_op(pd, OP_RX_STOP_DATA);
 	} else if (real_pos >= 0) {
-		data = i2c_op(pd, OP_RX);
+		pd->msg->buf[real_pos] = i2c_op(pd, OP_RX);
 	}
 
-	if (real_pos >= 0)
-		pd->msg->buf[real_pos] = data;
  done:
 	pd->pos++;
 	return pd->pos == (pd->msg->len + 2);
-- 
2.21.0.rc0.269.g1a574e7a288b

Re: [PATCH] i2c: sh_mobile: Fix compilation warning

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 791 bytes --]

On Thu, May 09, 2019 at 10:13:46AM +0530, Viresh Kumar wrote:
> This currently generates a warning:
> 
> drivers/i2c/busses/i2c-sh_mobile.c: In function 'sh_mobile_i2c_isr':
> drivers/i2c/busses/i2c-sh_mobile.c:399:26: warning: 'data' may be used uninitialized in this function [-Wmaybe-uninitialized]
> 
> Though the code looks okay and shouldn't ever use the variable
> uninitialized.
> 
> Fix the warning by moving the code around and getting rid of 'data'.
> 
> Compile tested only.
> 
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

Tested on a Renesas Lager board (R-Car H2). Dumping register sets
produces identical results.

Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

And code is actually cleaner now.

Applied to for-next, thanks!


[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

Re: [PATCH] i2c: sh_mobile: Fix compilation warning

[Viresh Kumar]

On 29-05-20, 14:12, Wolfram Sang wrote:
> On Thu, May 09, 2019 at 10:13:46AM +0530, Viresh Kumar wrote:
> > This currently generates a warning:
> > 
> > drivers/i2c/busses/i2c-sh_mobile.c: In function 'sh_mobile_i2c_isr':
> > drivers/i2c/busses/i2c-sh_mobile.c:399:26: warning: 'data' may be used uninitialized in this function [-Wmaybe-uninitialized]
> > 
> > Though the code looks okay and shouldn't ever use the variable
> > uninitialized.
> > 
> > Fix the warning by moving the code around and getting rid of 'data'.
> > 
> > Compile tested only.
> > 
> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> 
> Tested on a Renesas Lager board (R-Car H2). Dumping register sets
> produces identical results.
> 
> Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> 
> And code is actually cleaner now.
> 
> Applied to for-next, thanks!
> 

Almost after an year, wondering on how you reached this patch now :)

-- 
viresh

Re: [PATCH] i2c: sh_mobile: Fix compilation warning

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 239 bytes --]


> Almost after an year, wondering on how you reached this patch now :)

Another developer sent the same patch. And last time I was unsure if I
liked the new code better (for reasons I can't recall anymore); this
time it was clear to me.


[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]