Re: [PATCH] drm/amd/display: Fixed the unused-but-set-variable warning

On Thu, Mar 17, 2022 at 7:01 AM Aashish Sharma shraash@google.com wrote:

Fixed this kernel test robot warning:

drivers/gpu/drm/amd/amdgpu/../display/dmub/inc/dmub_cmd.h:2893:12: warning: variable 'temp' set but not used [-Wunused-but-set-variable]

Replaced the assignment to the unused temp variable with READ_ONCE() macro to flush the writes.

Signed-off-by: Aashish Sharma shraash@google.com

drivers/gpu/drm/amd/display/dmub/inc/dmub_cmd.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dmub/inc/dmub_cmd.h b/drivers/gpu/drm/amd/display/dmub/inc/dmub_cmd.h index 873ecd04e01d..b7981a781701 100644 --- a/drivers/gpu/drm/amd/display/dmub/inc/dmub_cmd.h +++ b/drivers/gpu/drm/amd/display/dmub/inc/dmub_cmd.h @@ -2913,13 +2913,12 @@ static inline void dmub_rb_flush_pending(const struct dmub_rb *rb) uint32_t wptr = rb->wrpt;

    while (rptr != wptr) {

•           uint64_t volatile *data = (uint64_t volatile *)((uint8_t *)(rb->base_address) + rptr);
  

•           uint64_t *data = (uint64_t volatile *)((uint8_t *)(rb->base_address) + rptr);
  

also drop the volatile in the typecast

            //uint64_t volatile *p = (uint64_t volatile *)data;

The above commented out code serves no purpose and should be removed as well.

Thanks, Guenter

•           uint64_t temp;
            uint8_t i;
  
            for (i = 0; i < DMUB_RB_CMD_SIZE / sizeof(uint64_t); i++)
  

•                   temp = *data++;
  

•                   (void)READ_ONCE(*data++);
  
            rptr += DMUB_RB_CMD_SIZE;
            if (rptr >= rb->capacity)
  

-- 2.35.1.723.g4982287a31-goog