On 2021-07-07 01:37, Jani Nikula wrote:
On Tue, 06 Jul 2021, Kuogee Hsieh <[email protected]> wrote:
From: Rajkumar Subbiah <[email protected]>
Commit 2f015ec6eab6 ("drm/dp_mst: Add sideband down request tracing +
selftests") added some debug code for sideband message tracing. But
it seems to have unintentionally changed the behavior on sideband
message
failure. It catches and returns failure only if DRM_UT_DP is enabled.
Otherwise it ignores the error code and returns success. So on an MST
unplug, the caller is unaware that the clear payload message failed
and
ends up waiting for 4 seconds for the response. Fixes the issue by
returning the proper error code.
Changes in V2:
-- Revise commit text as review comment
-- add Fixes text
Changes in V3:
-- remove "unlikely" optimization
Fixes: 2f015ec6eab6 ("drm/dp_mst: Add sideband down request tracing +
selftests")
Signed-off-by: Rajkumar Subbiah <[email protected]>
Signed-off-by: Kuogee Hsieh <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Reviewed-by: Jani Nikula <[email protected]>
---
Lyude,
Any comments from you?
Thanks,
drivers/gpu/drm/drm_dp_mst_topology.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c
b/drivers/gpu/drm/drm_dp_mst_topology.c
index 1590144..df91110 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -2887,11 +2887,13 @@ static int process_single_tx_qlock(struct
drm_dp_mst_topology_mgr *mgr,
idx += tosend + 1;
ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
- if (unlikely(ret) && drm_debug_enabled(DRM_UT_DP)) {
- struct drm_printer p = drm_debug_printer(DBG_PREFIX);
+ if (ret) {
+ if (drm_debug_enabled(DRM_UT_DP)) {
+ struct drm_printer p = drm_debug_printer(DBG_PREFIX);
- drm_printf(&p, "sideband msg failed to send\n");
- drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
+ drm_printf(&p, "sideband msg failed to send\n");
+ drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
+ }
return ret;
}
