[PATCH] drm/amd/display: fix 64 bit divide in freesync code

Alex Deucher alexander.deucher at amd.com
Thu Apr 7 19:50:29 UTC 2022


Use do_div() rather than a a 64 bit divide.

Fixes: 3fe5739db48843 ("drm/amd/display: Add flip interval workaround")
Reported-by: kernel test robot <lkp at intel.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Cc: Angus Wang <Angus.Wang at amd.com>
Cc: Anthony Koo <Anthony.Koo at amd.com>
Cc: Aric Cyr <Aric.Cyr at amd.com>
---
 drivers/gpu/drm/amd/display/modules/freesync/freesync.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/modules/freesync/freesync.c b/drivers/gpu/drm/amd/display/modules/freesync/freesync.c
index 0130f1879116..70f06fa8cc2b 100644
--- a/drivers/gpu/drm/amd/display/modules/freesync/freesync.c
+++ b/drivers/gpu/drm/amd/display/modules/freesync/freesync.c
@@ -1230,6 +1230,7 @@ void mod_freesync_handle_v_update(struct mod_freesync *mod_freesync,
 {
 	struct core_freesync *core_freesync = NULL;
 	unsigned int cur_timestamp_in_us;
+	unsigned long long tmp;
 
 	if ((mod_freesync == NULL) || (stream == NULL) || (in_out_vrr == NULL))
 		return;
@@ -1239,7 +1240,9 @@ void mod_freesync_handle_v_update(struct mod_freesync *mod_freesync,
 	if (in_out_vrr->supported == false)
 		return;
 
-	cur_timestamp_in_us = dm_get_timestamp(core_freesync->dc->ctx)/10;
+	tmp = dm_get_timestamp(core_freesync->dc->ctx);
+	do_div(tmp, 10);
+	cur_timestamp_in_us = tmp;
 
 	in_out_vrr->flip_interval.vsyncs_between_flip++;
 	in_out_vrr->flip_interval.v_update_timestamp_in_us = cur_timestamp_in_us;
-- 
2.35.1



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