Messages in this thread | | | Date | Tue, 13 Jul 2021 15:24:58 -0700 | From | khsieh@codeauro ... | Subject | Re: [PATCH v3] drm/dp_mst: Fix return code on sideband message failure |
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On 2021-07-07 01:37, Jani Nikula wrote: > On Tue, 06 Jul 2021, Kuogee Hsieh <khsieh@codeaurora.org> wrote: >> From: Rajkumar Subbiah <rsubbia@codeaurora.org> >> >> 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 <rsubbia@codeaurora.org> >> Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org> >> >> Reviewed-by: Stephen Boyd <swboyd@chromium.org> > > Reviewed-by: Jani Nikula <jani.nikula@intel.com> > > >> --- 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; >> }
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