Hello David, Thanks for your feedback. On 1/23/23 10:26, David Laight wrote: > From: Javier Martinez Canillas >> Sent: 21 January 2023 19:10 >> >> The sparse tool complains with the following warning: >> >> $ make M=drivers/gpu/drm/solomon/ C=2 >> CC [M] drivers/gpu/drm/solomon/ssd130x.o >> CHECK drivers/gpu/drm/solomon/ssd130x.c >> drivers/gpu/drm/solomon/ssd130x.c:363:21: warning: dubious: x & !y >> >> This seems to be a false positive in my opinion but still we can silence >> the tool while making the code easier to read. Let's also add a comment, >> to explain why the "com_seq" logical not is used rather than its value. >> >> Reported-by: Thomas Zimmermann <tzimmermann@xxxxxxx> >> Signed-off-by: Javier Martinez Canillas <javierm@xxxxxxxxxx> >> Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx> >> --- >> >> drivers/gpu/drm/solomon/ssd130x.c | 11 +++++++++-- >> 1 file changed, 9 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c >> index c3bf3a18302e..b16330a8b624 100644 >> --- a/drivers/gpu/drm/solomon/ssd130x.c >> +++ b/drivers/gpu/drm/solomon/ssd130x.c >> @@ -81,7 +81,7 @@ >> #define SSD130X_SET_PRECHARGE_PERIOD2_MASK GENMASK(7, 4) >> #define SSD130X_SET_PRECHARGE_PERIOD2_SET(val) FIELD_PREP(SSD130X_SET_PRECHARGE_PERIOD2_MASK, (val)) >> #define SSD130X_SET_COM_PINS_CONFIG1_MASK GENMASK(4, 4) >> -#define SSD130X_SET_COM_PINS_CONFIG1_SET(val) FIELD_PREP(SSD130X_SET_COM_PINS_CONFIG1_MASK, !(val)) >> +#define SSD130X_SET_COM_PINS_CONFIG1_SET(val) FIELD_PREP(SSD130X_SET_COM_PINS_CONFIG1_MASK, (val)) > > How about just changing !(val) to (val) ? 0 : 1 > It should shut the compiler up and is probably more descriptive. > I'm not sure if is more descriptive than what I have with this patch. As mentioned, I believe this really is a sparse false positive but given that need to change, I preferred to make it quite explicit with a new variable and a comment. This is only executed once at driver probe time anyways. > David -- Best regards, Javier Martinez Canillas Core Platforms Red Hat
