| Message ID | 1625008068-16458-1-git-send-email-khsieh@codeaurora.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] drm/dp_mst: Fix return code on sideband message failure | expand |
JFYI: will try to take a look at this at the start of next week On Tue, 2021-06-29 at 16:07 -0700, Kuogee Hsieh 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 > > 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> > --- > 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..8d97430 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 (unlikely(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; > } >
On Tue, 29 Jun 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 > > 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> > --- > 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..8d97430 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 (unlikely(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; > } Seems like a sensible thing to do. (I'd probably rip out the "unlikely" while at it, as it feels like unnecessary optimization, but *shrug*.) Reviewed-by: Jani Nikula <jani.nikula@intel.com>
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 1590144..8d97430 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 (unlikely(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; }