Intel-GFX Archive on lore.kernel.org
 help / color / Atom feed
From: Jesse Barnes <jbarnes@virtuousgeek.org>
To: intel-gfx@lists.freedesktop.org
Subject: [PATCH 4/8] drm/i915/dp: try to read receiver capabilities 3 times when detecting
Date: Fri,  1 Jul 2011 15:22:54 -0700
Message-ID: <1309558978-4704-5-git-send-email-jbarnes@virtuousgeek.org> (raw)
In-Reply-To: <1309558978-4704-1-git-send-email-jbarnes@virtuousgeek.org>

If ->detect is called too soon after a hot plug event, the sink may not
be ready yet.  So try up to 3 times with 1ms sleeps in between tries to
get the data (spec dictates that receivers must be ready to respond within
1ms and that sources should try 3 times).

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
---
 drivers/gpu/drm/i915/intel_dp.c |   15 ++++++++++-----
 1 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index dcef7fd..480e8d3 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1554,6 +1554,7 @@ static enum drm_connector_status
 ironlake_dp_detect(struct intel_dp *intel_dp)
 {
 	enum drm_connector_status status;
+	int ret, i;
 
 	/* Can't disconnect eDP, but you can close the lid... */
 	if (is_edp(intel_dp)) {
@@ -1564,12 +1565,16 @@ ironlake_dp_detect(struct intel_dp *intel_dp)
 	}
 
 	status = connector_status_disconnected;
-	if (intel_dp_aux_native_read(intel_dp,
-				     0x000, intel_dp->dpcd,
-				     sizeof (intel_dp->dpcd))
-	    == sizeof(intel_dp->dpcd)) {
-		if (intel_dp->dpcd[DP_DPCD_REV] != 0)
+	for (i = 0; i < 3; i++) {
+		ret = intel_dp_aux_native_read(intel_dp,
+					       0x000, intel_dp->dpcd,
+					       sizeof (intel_dp->dpcd));
+		if (ret == sizeof(intel_dp->dpcd) &&
+		    intel_dp->dpcd[DP_DPCD_REV] != 0) {
 			status = connector_status_connected;
+			break;
+		}
+		msleep(1);
 	}
 	DRM_DEBUG_KMS("DPCD: %hx%hx%hx%hx\n", intel_dp->dpcd[0],
 		      intel_dp->dpcd[1], intel_dp->dpcd[2], intel_dp->dpcd[3]);
-- 
1.7.4.1

  parent reply index

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-07-01 22:22 [RFC] misc DP fixes/changes Jesse Barnes
2011-07-01 22:22 ` [PATCH 1/8] drm/i915/dp: retry link status read 3 times on failure Jesse Barnes
2011-07-01 23:41   ` Keith Packard
2011-07-01 23:47     ` Jesse Barnes
2011-07-06  4:27   ` Eric Anholt
2011-07-06 16:09     ` Jesse Barnes
2011-07-01 22:22 ` [PATCH 2/8] drm/i915/dp: use DP DPCD defines when looking at DPCD values Jesse Barnes
2011-07-01 23:43   ` Keith Packard
2011-07-01 22:22 ` [PATCH 3/8] drm/i915/dp: read more receiver capability bits on hotplug Jesse Barnes
2011-07-01 23:45   ` Keith Packard
2011-07-01 22:22 ` Jesse Barnes [this message]
2011-07-01 23:45   ` [PATCH 4/8] drm/i915/dp: try to read receiver capabilities 3 times when detecting Keith Packard
2011-07-01 22:22 ` [PATCH 5/8] drm/i915/dp: set DP DPMS mode to "on" in ->commit Jesse Barnes
2011-07-01 23:46   ` Keith Packard
2011-07-01 22:22 ` [PATCH 6/8] drm/i915/dp: clear DP encoder CRTC if the receiver disappears Jesse Barnes
2011-07-01 23:48   ` Keith Packard
2011-07-01 23:59     ` Jesse Barnes
2011-07-02  0:31       ` Keith Packard
2011-07-01 22:22 ` [PATCH 7/8] drm/i915/dp: rename dpms_mode to receiver_configured Jesse Barnes
2011-07-01 23:50   ` Keith Packard
2011-07-01 22:22 ` [PATCH 8/8] drm/i915/dp: clear receiver_configured when link training fails Jesse Barnes
2011-07-01 23:51   ` Keith Packard
2011-07-01 23:39 ` [RFC] misc DP fixes/changes Keith Packard

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=1309558978-4704-5-git-send-email-jbarnes@virtuousgeek.org \
    --to=jbarnes@virtuousgeek.org \
    --cc=intel-gfx@lists.freedesktop.org \
    /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

Intel-GFX Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/intel-gfx/0 intel-gfx/git/0.git
	git clone --mirror https://lore.kernel.org/intel-gfx/1 intel-gfx/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 intel-gfx intel-gfx/ https://lore.kernel.org/intel-gfx \
		intel-gfx@lists.freedesktop.org
	public-inbox-index intel-gfx

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.freedesktop.lists.intel-gfx


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git