Patch "drm/i915: Fix HPD polling, reenabling the output poll work as needed" has been added to the 6.4-stable tree

[gregkh at linuxfoundation.org]

This is a note to let you know that I've just added the patch titled

    drm/i915: Fix HPD polling, reenabling the output poll work as needed

to the 6.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-i915-fix-hpd-polling-reenabling-the-output-poll-work-as-needed.patch
and it can be found in the queue-6.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable at vger.kernel.org> know about it.


>From 1dcc437427bbcebc8381226352f7ade08a271191 Mon Sep 17 00:00:00 2001
From: Imre Deak <imre.deak at intel.com>
Date: Tue, 22 Aug 2023 14:30:15 +0300
Subject: drm/i915: Fix HPD polling, reenabling the output poll work as needed
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Imre Deak <imre.deak at intel.com>

commit 1dcc437427bbcebc8381226352f7ade08a271191 upstream.

After the commit in the Fixes: line below, HPD polling stopped working
on i915, since after that change calling drm_kms_helper_poll_enable()
doesn't restart drm_mode_config::output_poll_work if the work was
stopped (no connectors needing polling) and enabling polling for a
connector (during runtime suspend or detecting an HPD IRQ storm).

After the above change calling drm_kms_helper_poll_enable() is a nop
after it's been called already and polling for some connectors was
disabled/re-enabled.

Fix this by calling drm_kms_helper_poll_reschedule() added in the
previous patch instead, which reschedules the work whenever expected.

Fixes: d33a54e3991d ("drm/probe_helper: sort out poll_running vs poll_enabled")
CC: stable at vger.kernel.org # 6.4+
Cc: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
Cc: dri-devel at lists.freedesktop.org
Reviewed-by: Jouni Högander <jouni.hogander at intel.com>
Signed-off-by: Imre Deak <imre.deak at intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230822113015.41224-2-imre.deak@intel.com
(cherry picked from commit 50452f2f76852322620b63e62922b85e955abe94)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 drivers/gpu/drm/i915/display/intel_hotplug.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/i915/display/intel_hotplug.c
+++ b/drivers/gpu/drm/i915/display/intel_hotplug.c
@@ -210,7 +210,7 @@ intel_hpd_irq_storm_switch_to_polling(st
 
 	/* Enable polling and queue hotplug re-enabling. */
 	if (hpd_disabled) {
-		drm_kms_helper_poll_enable(&dev_priv->drm);
+		drm_kms_helper_poll_reschedule(&dev_priv->drm);
 		mod_delayed_work(system_wq, &dev_priv->display.hotplug.reenable_work,
 				 msecs_to_jiffies(HPD_STORM_REENABLE_DELAY));
 	}
@@ -644,7 +644,7 @@ static void i915_hpd_poll_init_work(stru
 	drm_connector_list_iter_end(&conn_iter);
 
 	if (enabled)
-		drm_kms_helper_poll_enable(&dev_priv->drm);
+		drm_kms_helper_poll_reschedule(&dev_priv->drm);
 
 	mutex_unlock(&dev_priv->drm.mode_config.mutex);
 


Patches currently in stable-queue which might be from imre.deak at intel.com are

queue-6.4/drm-i915-fix-hpd-polling-reenabling-the-output-poll-work-as-needed.patch
queue-6.4/drm-add-an-hpd-poll-helper-to-reschedule-the-poll-work.patch