From: Leo Chen leo.chen@amd.com
[ Upstream commit 0fe33e115fec305c35c66b78ad26e3755ab54b9c ]
[Why] A race condition occurs between cursor movement and vertical interrupt control thread from OS, with both threads trying to exit IPS2. Vertical interrupt control thread clears the prev driver allow signal while not fully finishing the IPS2 exit process.
[How] We want to detect all the allow signals have been cleared before we perform the full exit.
Reviewed-by: Nicholas Kazlauskas nicholas.kazlauskas@amd.com Signed-off-by: Leo Chen leo.chen@amd.com Signed-off-by: Roman Li roman.li@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c | 6 ++++-- drivers/gpu/drm/amd/display/dmub/inc/dmub_cmd.h | 3 ++- 2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c index ded13026c8ff7..c46100c83d0a7 100644 --- a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c +++ b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c @@ -1291,6 +1291,8 @@ static void dc_dmub_srv_notify_idle(const struct dc *dc, bool allow_idle)
memset(&new_signals, 0, sizeof(new_signals));
+ new_signals.bits.allow_idle = 1; /* always set */ + if (dc->config.disable_ips == DMUB_IPS_ENABLE || dc->config.disable_ips == DMUB_IPS_DISABLE_DYNAMIC) { new_signals.bits.allow_pg = 1; @@ -1386,7 +1388,7 @@ static void dc_dmub_srv_exit_low_power_state(const struct dc *dc) */ dc_dmub_srv->needs_idle_wake = false;
- if (prev_driver_signals.bits.allow_ips2 && + if ((prev_driver_signals.bits.allow_ips2 || prev_driver_signals.all == 0) && (!dc->debug.optimize_ips_handshake || ips_fw->signals.bits.ips2_commit || !ips_fw->signals.bits.in_idle)) { DC_LOG_IPS( @@ -1447,7 +1449,7 @@ static void dc_dmub_srv_exit_low_power_state(const struct dc *dc) }
dc_dmub_srv_notify_idle(dc, false); - if (prev_driver_signals.bits.allow_ips1) { + if (prev_driver_signals.bits.allow_ips1 || prev_driver_signals.all == 0) { DC_LOG_IPS( "wait for IPS1 commit clear (ips1_commit=%d ips2_commit=%d)", ips_fw->signals.bits.ips1_commit, 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 5ff0a865705f5..a11bfef3ab50d 100644 --- a/drivers/gpu/drm/amd/display/dmub/inc/dmub_cmd.h +++ b/drivers/gpu/drm/amd/display/dmub/inc/dmub_cmd.h @@ -743,7 +743,8 @@ union dmub_shared_state_ips_driver_signals { uint32_t allow_ips1 : 1; /**< 1 is IPS1 is allowed */ uint32_t allow_ips2 : 1; /**< 1 is IPS1 is allowed */ uint32_t allow_z10 : 1; /**< 1 if Z10 is allowed */ - uint32_t reserved_bits : 28; /**< Reversed bits */ + uint32_t allow_idle : 1; /**< 1 if driver is allowing idle */ + uint32_t reserved_bits : 27; /**< Reversed bits */ } bits; uint32_t all; };