[Intel-gfx] Patch "drm/i915: Allow switching away via vga-switcheroo if uninitialized" has been added to the 6.1-stable tree

[gregkh at linuxfoundation.org]

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

    drm/i915: Allow switching away via vga-switcheroo if uninitialized

to the 6.1-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-allow-switching-away-via-vga-switcheroo-if-uninitialized.patch
and it can be found in the queue-6.1 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 a273e95721e96885971a05f1b34cb6d093904d9d Mon Sep 17 00:00:00 2001
From: Thomas Zimmermann <tzimmermann at suse.de>
Date: Mon, 16 Jan 2023 12:54:23 +0100
Subject: drm/i915: Allow switching away via vga-switcheroo if uninitialized
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Thomas Zimmermann <tzimmermann at suse.de>

commit a273e95721e96885971a05f1b34cb6d093904d9d upstream.

Always allow switching away via vga-switcheroo if the display is
uninitalized. Instead prevent switching to i915 if the device has
not been initialized.

This issue was introduced by commit 5df7bd130818 ("drm/i915: skip
display initialization when there is no display") protected, which
protects code paths from being executed on uninitialized devices.
In the case of vga-switcheroo, we want to allow a switch away from
i915's device. So run vga_switcheroo_process_delayed_switch() and
test in the switcheroo callbacks if the i915 device is available.

Fixes: 5df7bd130818 ("drm/i915: skip display initialization when there is no display")
Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
Cc: Radhakrishna Sripada <radhakrishna.sripada at intel.com>
Cc: Lucas De Marchi <lucas.demarchi at intel.com>
Cc: José Roberto de Souza <jose.souza at intel.com>
Cc: Jani Nikula <jani.nikula at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Jani Nikula <jani.nikula at linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
Cc: "Ville Syrjälä" <ville.syrjala at linux.intel.com>
Cc: Manasi Navare <manasi.d.navare at intel.com>
Cc: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
Cc: Imre Deak <imre.deak at intel.com>
Cc: "Jouni Högander" <jouni.hogander at intel.com>
Cc: Uma Shankar <uma.shankar at intel.com>
Cc: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
Cc: "Jason A. Donenfeld" <Jason at zx2c4.com>
Cc: Matt Roper <matthew.d.roper at intel.com>
Cc: Ramalingam C <ramalingam.c at intel.com>
Cc: Thomas Zimmermann <tzimmermann at suse.de>
Cc: Andi Shyti <andi.shyti at linux.intel.com>
Cc: Andrzej Hajda <andrzej.hajda at intel.com>
Cc: "José Roberto de Souza" <jose.souza at intel.com>
Cc: Julia Lawall <Julia.Lawall at inria.fr>
Cc: intel-gfx at lists.freedesktop.org
Cc: <stable at vger.kernel.org> # v5.14+
Link: https://patchwork.freedesktop.org/patch/msgid/20230116115425.13484-2-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 drivers/gpu/drm/i915/i915_driver.c     |    5 +----
 drivers/gpu/drm/i915/i915_switcheroo.c |    6 +++++-
 2 files changed, 6 insertions(+), 5 deletions(-)

--- a/drivers/gpu/drm/i915/i915_driver.c
+++ b/drivers/gpu/drm/i915/i915_driver.c
@@ -1070,12 +1070,9 @@ static int i915_driver_open(struct drm_d
  */
 static void i915_driver_lastclose(struct drm_device *dev)
 {
-	struct drm_i915_private *i915 = to_i915(dev);
-
 	intel_fbdev_restore_mode(dev);
 
-	if (HAS_DISPLAY(i915))
-		vga_switcheroo_process_delayed_switch();
+	vga_switcheroo_process_delayed_switch();
 }
 
 static void i915_driver_postclose(struct drm_device *dev, struct drm_file *file)
--- a/drivers/gpu/drm/i915/i915_switcheroo.c
+++ b/drivers/gpu/drm/i915/i915_switcheroo.c
@@ -19,6 +19,10 @@ static void i915_switcheroo_set_state(st
 		dev_err(&pdev->dev, "DRM not initialized, aborting switch.\n");
 		return;
 	}
+	if (!HAS_DISPLAY(i915)) {
+		dev_err(&pdev->dev, "Device state not initialized, aborting switch.\n");
+		return;
+	}
 
 	if (state == VGA_SWITCHEROO_ON) {
 		drm_info(&i915->drm, "switched on\n");
@@ -44,7 +48,7 @@ static bool i915_switcheroo_can_switch(s
 	 * locking inversion with the driver load path. And the access here is
 	 * completely racy anyway. So don't bother with locking for now.
 	 */
-	return i915 && atomic_read(&i915->drm.open_count) == 0;
+	return i915 && HAS_DISPLAY(i915) && atomic_read(&i915->drm.open_count) == 0;
 }
 
 static const struct vga_switcheroo_client_ops i915_switcheroo_ops = {


Patches currently in stable-queue which might be from tzimmermann at suse.de are

queue-6.1/drm-i915-allow-switching-away-via-vga-switcheroo-if-uninitialized.patch