[PATCH 1/1][SRU][Unstable/OEM-5.17] drm/amd/display: Only set PSR version when valid

[You-Sheng Yang]

From: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>

BugLink: https://bugs.launchpad.net/bugs/1969407

[Why]
DMCUB will hang if we send a PSR unsupported set version command.

This can occur if we fall-through into the default case in the switch
statement for PSR version.

[How]
Add an unsupported check after the switch statement.

Tested-by: Daniel Wheeler <daniel.wheeler at amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo at amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira at amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
(cherry picked from commit 1210b17dd4ece454d68a9283f391e3b036aeb010)
Signed-off-by: You-Sheng Yang <vicamo.yang at canonical.com>
---
 drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c b/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
index 87ed48d5530d..8bd265b40847 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
@@ -138,6 +138,10 @@ static bool dmub_psr_set_version(struct dmub_psr *dmub, struct dc_stream_state *
 		cmd.psr_set_version.psr_set_version_data.version = PSR_VERSION_UNSUPPORTED;
 		break;
 	}
+
+	if (cmd.psr_set_version.psr_set_version_data.version == PSR_VERSION_UNSUPPORTED)
+		return false;
+
 	cmd.psr_set_version.psr_set_version_data.cmd_version = DMUB_CMD_PSR_CONTROL_VERSION_1;
 	cmd.psr_set_version.psr_set_version_data.panel_inst = panel_inst;
 	cmd.psr_set_version.header.payload_bytes = sizeof(struct dmub_cmd_psr_set_version_data);
-- 
2.34.1