From: Lyude Paul <lyude@redhat.com>
To: Kuogee Hsieh <khsieh@codeaurora.org>,
robdclark@gmail.com, sean@poorly.run, swboyd@chromium.org
Cc: abhinavk@codeaurora.org, aravindh@codeaurora.org,
rsubbia@codeaurora.org, rnayak@codeaurora.org,
freedreno@lists.freedesktop.org, airlied@linux.ie,
daniel@ffwll.ch, maarten.lankhorst@linux.intel.com,
mripard@kernel.org, tzimmermann@suse.de,
dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] drm/dp_mst: Fix return code on sideband message failure
Date: Fri, 02 Jul 2021 15:50:42 -0400 [thread overview]
Message-ID: <ecd705dad88c4ea1331edc269f136aca4a5e63d5.camel@redhat.com> (raw)
In-Reply-To: <1625008068-16458-1-git-send-email-khsieh@codeaurora.org>
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
next prev parent reply other threads:[~2021-07-02 19:50 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
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 [this message]
2021-07-05 9:07 ` Jani Nikula
-- strict thread matches above, loose matches on Subject: below --
2021-06-29 22:55 Kuogee Hsieh
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