drm/amd/display: Full exit out of IPS2 when all allow signals have been cleared

[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>

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 8486c144d81ca32e0806c9ab9d117896902bde9d..f0417ee6fcf8e8e84644193ba4dd2968c44780b9 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
+++ b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
@@ -1295,6 +1295,8 @@ 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;
@@ -1390,7 +1392,7 @@ 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(
@@ -1451,7 +1453,7 @@ 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=%u ips2_commit=%u)",
                                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 f9e82c4f8deb65679591e4870b4db62237e4de0d..6edd3d34c7b59c9f85ff916dd15820022eea125d 100644 (file)
--- a/drivers/gpu/drm/amd/display/dmub/inc/dmub_cmd.h
+++ b/drivers/gpu/drm/amd/display/dmub/inc/dmub_cmd.h
@@ -752,7 +752,8 @@ 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;
 };