drm/amd/display: Wake DMCUB before sending a command

[Why]
We can hang in place trying to send commands when the DMCUB isn't
powered on.

[How]
For functions that execute within a DC context or DC lock we can
wrap the direct calls to dm_execute_dmub_cmd/list with code that
exits idle power optimizations and reallows once we're done with
the command submission on success.

For DM direct submissions the DM will need to manage the enter/exit
sequencing manually.

We cannot invoke a DMCUB command directly within the DM execution
helper or we can deadlock.

Cc: Mario Limonciello <mario.limonciello@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Reviewed-by: Hansen Dsouza <hansen.dsouza@amd.com>
Acked-by: Wayne Lin <wayne.lin@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 40 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.h b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.h
index b63cba6235fc..784ca3e44414 100644
--- a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.h
+++ b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.h
@@ -106,4 +106,44 @@ bool dc_dmub_srv_is_hw_pwr_up(struct dc_dmub_srv *dc_dmub_srv, bool wait);
 void dc_dmub_srv_apply_idle_power_optimizations(const struct dc *dc, bool allow_idle);
 
 void dc_dmub_srv_set_power_state(struct dc_dmub_srv *dc_dmub_srv, enum dc_acpi_cm_power_state powerState);
+
+/**
+ * dc_wake_and_execute_dmub_cmd() - Wrapper for DMUB command execution.
+ *
+ * Refer to dc_wake_and_execute_dmub_cmd_list() for usage and limitations,
+ * This function is a convenience wrapper for a single command execution.
+ *
+ * @ctx: DC context
+ * @cmd: The command to send/receive
+ * @wait_type: The wait behavior for the execution
+ *
+ * Return: true on command submission success, false otherwise
+ */
+bool dc_wake_and_execute_dmub_cmd(const struct dc_context *ctx, union dmub_rb_cmd *cmd,
+				  enum dm_dmub_wait_type wait_type);
+
+/**
+ * dc_wake_and_execute_dmub_cmd_list() - Wrapper for DMUB command list execution.
+ *
+ * If the DMCUB hardware was asleep then it wakes the DMUB before
+ * executing the command and attempts to re-enter if the command
+ * submission was successful.
+ *
+ * This should be the preferred command submission interface provided
+ * the DC lock is acquired.
+ *
+ * Entry/exit out of idle power optimizations would need to be
+ * manually performed otherwise through dc_allow_idle_optimizations().
+ *
+ * @ctx: DC context
+ * @count: Number of commands to send/receive
+ * @cmd: Array of commands to send
+ * @wait_type: The wait behavior for the execution
+ *
+ * Return: true on command submission success, false otherwise
+ */
+bool dc_wake_and_execute_dmub_cmd_list(const struct dc_context *ctx, unsigned int count,
+				       union dmub_rb_cmd *cmd, enum dm_dmub_wait_type wait_type);
+
+
 #endif /* _DMUB_DC_SRV_H_ */