* [PATCH v2] drm/dp_mst: Fix return code on sideband message failure
@ 2021-06-29 23:07 Kuogee Hsieh
2021-07-02 19:50 ` Lyude Paul
2021-07-05 9:07 ` Jani Nikula
0 siblings, 2 replies; 4+ messages in thread
From: Kuogee Hsieh @ 2021-06-29 23:07 UTC (permalink / raw)
To: robdclark, sean, swboyd, lyude
Cc: rnayak, tzimmermann, airlied, dri-devel, linux-kernel, abhinavk,
khsieh, aravindh, freedreno, rsubbia
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;
}
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] drm/dp_mst: Fix return code on sideband message failure
2021-06-29 23:07 [PATCH v2] drm/dp_mst: Fix return code on sideband message failure Kuogee Hsieh
@ 2021-07-02 19:50 ` Lyude Paul
2021-07-05 9:07 ` Jani Nikula
1 sibling, 0 replies; 4+ messages in thread
From: Lyude Paul @ 2021-07-02 19:50 UTC (permalink / raw)
To: Kuogee Hsieh, robdclark, sean, swboyd
Cc: rnayak, tzimmermann, airlied, dri-devel, linux-kernel, abhinavk,
aravindh, freedreno, rsubbia
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;
> }
>
--
Cheers,
Lyude Paul (she/her)
Software Engineer at Red Hat
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] drm/dp_mst: Fix return code on sideband message failure
2021-06-29 23:07 [PATCH v2] drm/dp_mst: Fix return code on sideband message failure Kuogee Hsieh
2021-07-02 19:50 ` Lyude Paul
@ 2021-07-05 9:07 ` Jani Nikula
1 sibling, 0 replies; 4+ messages in thread
From: Jani Nikula @ 2021-07-05 9:07 UTC (permalink / raw)
To: Kuogee Hsieh, robdclark, sean, swboyd, lyude
Cc: rnayak, airlied, linux-kernel, abhinavk, khsieh, dri-devel,
tzimmermann, aravindh, freedreno, rsubbia
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>
--
Jani Nikula, Intel Open Source Graphics Center
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v2] drm/dp_mst: Fix return code on sideband message failure
@ 2021-06-29 22:55 Kuogee Hsieh
0 siblings, 0 replies; 4+ messages in thread
From: Kuogee Hsieh @ 2021-06-29 22:55 UTC (permalink / raw)
To: robdclark, sean, swboyd
Cc: rnayak, tzimmermann, airlied, dri-devel, linux-kernel, abhinavk,
khsieh, aravindh, freedreno, rsubbia
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.
This change 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;
}
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
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2021-06-29 23:07 [PATCH v2] drm/dp_mst: Fix return code on sideband message failure Kuogee Hsieh
2021-07-02 19:50 ` Lyude Paul
2021-07-05 9:07 ` Jani Nikula
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