From: Koba Ko <koba.ko@canonical.com>
To: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <mripard@kernel.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
Lyude Paul <lyude@redhat.com>,
dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Cc: anthony.wong@canonical.com
Subject: [PATCH V4] drm/dp_mst: Retrieve extended DPCD caps for topology manager
Date: Tue, 22 Sep 2020 14:53:13 +0800 [thread overview]
Message-ID: <20200922065313.4794-1-koba.ko@canonical.com> (raw)
As per DP-1.3, First check DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT.
If DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT is 1,read the DP_DP13_DPCD_REV to
get the faster capability.
If DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT is 0,read DP_DPCD_REV.
Signed-off-by: Koba Ko <koba.ko@canonical.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
---
drivers/gpu/drm/drm_dp_mst_topology.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index e87542533640..63f8809b9aa4 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -3686,9 +3686,9 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
WARN_ON(mgr->mst_primary);
/* get dpcd info */
- ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
- if (ret != DP_RECEIVER_CAP_SIZE) {
- DRM_DEBUG_KMS("failed to read DPCD\n");
+ ret = drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd);
+ if (ret < 0) {
+ drm_dbg_kms(mgr->dev, "failed to read DPCD, ret %d\n", ret);
goto out_unlock;
}
--
2.17.1
next reply other threads:[~2020-09-22 6:53 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-22 6:53 Koba Ko [this message]
2020-09-22 18:01 ` [PATCH V4] drm/dp_mst: Retrieve extended DPCD caps for topology manager Lyude Paul
2020-09-23 2:16 ` Koba Ko
2020-09-23 14:17 ` Lyude Paul
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200922065313.4794-1-koba.ko@canonical.com \
--to=koba.ko@canonical.com \
--cc=airlied@linux.ie \
--cc=anthony.wong@canonical.com \
--cc=daniel@ffwll.ch \
--cc=dri-devel@lists.freedesktop.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lyude@redhat.com \
--cc=maarten.lankhorst@linux.intel.com \
--cc=mripard@kernel.org \
--cc=tzimmermann@suse.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).