From: Wyatt Wood Date: Mon, 22 Mar 2021 18:02:56 +0000 (-0400) Subject: drm/amd/display: Add delay in dmub_srv_send_gpint_command X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=6bdb2e3821616329125fea108c48fe5fe54aaafc;p=linux.git 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 --- 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 e36e89157703e..1cbb125b4063b 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; }