From 6bdb2e3821616329125fea108c48fe5fe54aaafc Mon Sep 17 00:00:00 2001 From: Wyatt Wood Date: Mon, 22 Mar 2021 14:02:56 -0400 Subject: [PATCH] drm/amd/display: Add delay in dmub_srv_send_gpint_command [Why] Today a parameter is passed to dmub_srv_send_gpint_command which specifies the max amount of time to wait for the command to be acked. This parameter instead specifies the number of times to check if the command was acked. We wish to add a lower bound to the timeout, which can be accomplished by using a delay or a timestamp. It has been decided to use udelay instead of a timestamp simply because we don't want to expose a high precision counter if it doesn't yield large benefits. [How] Add udelay(1) between each for loop iteration. Signed-off-by: Wyatt Wood Reviewed-by: Nicholas Kazlauskas Acked-by: Qingqing Zhuo Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c b/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c index e36e89157703..1cbb125b4063 100644 --- a/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c +++ b/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c @@ -647,6 +647,8 @@ dmub_srv_send_gpint_command(struct dmub_srv *dmub, dmub->hw_funcs.set_gpint(dmub, reg); for (i = 0; i < timeout_us; ++i) { + udelay(1); + if (dmub->hw_funcs.is_gpint_acked(dmub, reg)) return DMUB_STATUS_OK; } -- 2.34.1