Attachment 123537 Details for Bug 94014 – possible fix

[patch] possible fix

0001-i915-hdmi-wait-up-to-90ms-for-hotplug-detect.patch (text/plain), 2.09 KB, created by Luke on 2016-05-07 16:36:32 UTC

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Creator: Luke

Created: 2016-05-07 16:36:32 UTC

Size: 2.09 KB

patch

obsolete

>From 9be1d7bcd4167e9e2cc1d6218080963e514f28d4 Mon Sep 17 00:00:00 2001
>From: Luke Diamand <luke@diamand.org>
>Date: Sat, 7 May 2016 15:19:41 +0100
>Subject: [PATCH] i915: hdmi: wait up to 90ms for hotplug detect
>
>On some monitors (e.g. Acer G246HYL) we need to
>wait for up to 90ms for hotplug detection. Otherwise we
>can end up with a blank screen after coming out of
>standby.
>
>The previous version of this code would only wait for
>up to 70ms, and possibly less than that, which doesn't
>seem to be enough (by experiment).
>
>Experimentally this section of code actually always
>either waits 90ms and then fails, or succeeds
>immediately after having previously failed.
>
>Reference: https://bugs.freedesktop.org/show_bug.cgi?id=94014
>Signed-off-by: Luke Diamand <luke@diamand.org>
>---
> drivers/gpu/drm/i915/intel_hdmi.c | 18 +++++++++++++-----
> 1 file changed, 13 insertions(+), 5 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
>index a0d8dae..78f0549 100644
>--- a/drivers/gpu/drm/i915/intel_hdmi.c
>+++ b/drivers/gpu/drm/i915/intel_hdmi.c
>@@ -1401,22 +1401,30 @@ intel_hdmi_detect(struct drm_connector *connector, bool force)
> 	struct intel_hdmi *intel_hdmi = intel_attached_hdmi(connector);
> 	struct drm_i915_private *dev_priv = to_i915(connector->dev);
> 	bool live_status = false;
>-	unsigned int try;
>+	unsigned long maxwait = msecs_to_jiffies(90);
>+	unsigned long timeout = jiffies + maxwait;
>+	unsigned long start = jiffies;
> 
> 	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n",
> 		      connector->base.id, connector->name);
> 
> 	intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS);
> 
>-	for (try = 0; !live_status && try < 9; try++) {
>-		if (try)
>-			msleep(10);
>+	while (time_before(jiffies, timeout)) {
>+
> 		live_status = intel_digital_port_connected(dev_priv,
> 				hdmi_to_dig_port(intel_hdmi));
>+
>+		if (live_status)
>+			break;
>+
>+		usleep_range(5000,10000);
> 	}
> 
> 	if (!live_status)
>-		DRM_DEBUG_KMS("Live status not up!");
>+		DRM_DEBUG_KMS("%s: Live status not up after %d ms!",
>+			__func__,
>+			jiffies_to_msecs(jiffies-start));
> 
> 	intel_hdmi_unset_edid(connector);
> 
>-- 
>2.8.1.218.gd2cea43.dirty
>

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Attachments on bug 94014: 121542 | 121543 | 122185 | 123537 | 123538 | 124010

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