On Sun, Mar 14, 2021 at 08:59:41AM -0600, Edmundo Carmona Antoranz wrote:
> Since its introduction in 5449c685a4b3 (Staging: Add pristine
> upstream vt6655 driver sources, 2009-04-25), the values
> stored in variable byData have never been read in the macro
> PCAvDelayByIO. By removing it, we are getting rid of a warning:
>
> drivers/staging/vt6655/upc.h:45:16: warning: variable ‘byData’ set but not used [-Wunused-but-set-variable]
>
> Signed-off-by: Edmundo Carmona Antoranz <eantoranz@xxxxxxxxx>
> ---
> drivers/staging/vt6655/upc.h | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/staging/vt6655/upc.h b/drivers/staging/vt6655/upc.h
> index e086ec6e77f7..f00d0fd90003 100644
> --- a/drivers/staging/vt6655/upc.h
> +++ b/drivers/staging/vt6655/upc.h
> @@ -42,14 +42,13 @@
>
> #define PCAvDelayByIO(uDelayUnit) \
> do { \
> - unsigned char byData; \
> unsigned long ii; \
> \
> if (uDelayUnit <= 50) { \
> udelay(uDelayUnit); \
> } else { \
> for (ii = 0; ii < (uDelayUnit); ii++) \
> - byData = inb(0x61); \
> + inb(0x61); \
Are you sure that the compiler does not make the inb() now go away?
This is being done like this for a very specific reason, the value read
does not matter, but you have to read something.
thanks,
greg k-h
