From d6cde775313143892e85546eaa55b627a333b519 Mon Sep 17 00:00:00 2001
From: Aashish Sharma <shraash@google.com>
Date: Thu, 24 Mar 2022 19:10:31 +0530
Subject: drm/amd/display: Fix unused-but-set-variable warning
Git-commit: 7da7b02e97c8e4332a497a179575db6892cbeca5
Patch-mainline: v5.19-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
Fix the kernel test robot warning below:
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. READ_ONCE() helps avoid the use of
volatile and makes it obvious from the code that the read here is
intentional. Also verified on x86 that the generated code is exactly the
same as before.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Aashish Sharma <shraash@google.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/amd/display/dmub/inc/dmub_cmd.h | 6 ++----
1 file changed, 2 insertions(+), 4 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 9b5db16b2619..95f1c7198dd3 100644
--- a/drivers/gpu/drm/amd/display/dmub/inc/dmub_cmd.h
+++ b/drivers/gpu/drm/amd/display/dmub/inc/dmub_cmd.h
@@ -2962,9 +2962,7 @@ 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 volatile *p = (uint64_t volatile *)data;
- uint64_t temp;
+ uint64_t *data = (uint64_t *)((uint8_t *)(rb->base_address) + rptr);
uint8_t i;
/* Don't remove this.
@@ -2972,7 +2970,7 @@ static inline void dmub_rb_flush_pending(const struct dmub_rb *rb)
* for this function to be effective.
*/
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)
--
2.38.1