drm/i915: increase the tries for HDMI hotplug live status checking

zcwang · jnikula · commit 3d8acd1f667b · 2015-12-30T13:58:37.000+02:00
The total delay of HDMI hotplug detecting with 30ms is sometimes not enoughtfor HDMI live status up with specific HDMI monitors in BSW platform. After doing experiments for following monitors, it needs 80ms at least for those worst cases. Lenovo L246 1xwA (4 failed, necessary hot-plug delay: 58/40/60/40ms) Philips HH2AP (9 failed, necessary hot-plug delay: 80/50/50/60/46/40/58/58/39ms) BENQ ET-0035-N (6 failed, necessary hot-plug delay: 60/50/50/80/80/40ms) DELL U2713HM (2 failed, necessary hot-plug delay: 58/59ms) HP HP-LP2475w (5 failed, necessary hot-plug delay: 70/50/40/60/40ms) It looks like 70-80 ms is BSW platform needs in some bad cases of the monitors at this end (8 times delay at most). Keep less than 100ms for HDCP pulse HPD low (with at least 100ms) to respond a plug out. Reviewed-by: Cooper Chiou <cooper.chiou@intel.com> Tested-by: Gary Wang <gary.c.wang@intel.com> Cc: Gavin Hindman <gavin.hindman@intel.com> Cc: Sonika Jindal <sonika.jindal@intel.com> Cc: Shashank Sharma <shashank.sharma@intel.com> Cc: Shobhit Kumar <shobhit.kumar@intel.com> Signed-off-by: Gary Wang <gary.c.wang@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1450858295-12804-1-git-send-email-gary.c.wang@intel.com Tested-by: Shobhit Kumar <shobhit.kumar@intel.com> Cc: drm-intel-fixes@lists.freedesktop.org Fixes: 237ed86 ("drm/i915: Check live status before reading edid") Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> (cherry picked from commit f8d03ea) [Jani: undo the file mode change of the original commit] Signed-off-by: Jani Nikula <jani.nikula@intel.com>
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -1381,7 +1381,7 @@ intel_hdmi_detect(struct drm_connector *connector, bool force)
 
 	intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS);
 
-	for (try = 0; !live_status && try < 4; try++) {
+	for (try = 0; !live_status && try < 9; try++) {
 		if (try)
 			msleep(10);
 		live_status = intel_digital_port_connected(dev_priv,
