Patch "drm/mgag200: Bind I2C lifetime to DRM device" 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/mgag200: Bind I2C lifetime to DRM device

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-mgag200-bind-i2c-lifetime-to-drm-device.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 eb1ae34e48a09b7a1179c579aed042b032e408f4 Mon Sep 17 00:00:00 2001
From: Thomas Zimmermann <tzimmermann at suse.de>
Date: Mon, 13 May 2024 14:51:07 +0200
Subject: drm/mgag200: Bind I2C lifetime to DRM device

From: Thomas Zimmermann <tzimmermann at suse.de>

commit eb1ae34e48a09b7a1179c579aed042b032e408f4 upstream.

Managed cleanup with devm_add_action_or_reset() will release the I2C
adapter when the underlying Linux device goes away. But the connector
still refers to it, so this cleanup leaves behind a stale pointer
in struct drm_connector.ddc.

Bind the lifetime of the I2C adapter to the connector's lifetime by
using DRM's managed release. When the DRM device goes away (after
the Linux device) DRM will first clean up the connector and then
clean up the I2C adapter.

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe at redhat.com>
Fixes: b279df242972 ("drm/mgag200: Switch I2C code to managed cleanup")
Cc: Thomas Zimmermann <tzimmermann at suse.de>
Cc: Jocelyn Falempe <jfalempe at redhat.com>
Cc: Dave Airlie <airlied at redhat.com>
Cc: dri-devel at lists.freedesktop.org
Cc: <stable at vger.kernel.org> # v6.0+
Link: https://patchwork.freedesktop.org/patch/msgid/20240513125620.6337-3-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 drivers/gpu/drm/mgag200/mgag200_i2c.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/mgag200/mgag200_i2c.c
+++ b/drivers/gpu/drm/mgag200/mgag200_i2c.c
@@ -31,6 +31,8 @@
 #include <linux/i2c.h>
 #include <linux/pci.h>
 
+#include <drm/drm_managed.h>
+
 #include "mgag200_drv.h"
 
 static int mga_i2c_read_gpio(struct mga_device *mdev)
@@ -86,7 +88,7 @@ static int mga_gpio_getscl(void *data)
 	return (mga_i2c_read_gpio(mdev) & i2c->clock) ? 1 : 0;
 }
 
-static void mgag200_i2c_release(void *res)
+static void mgag200_i2c_release(struct drm_device *dev, void *res)
 {
 	struct mga_i2c_chan *i2c = res;
 
@@ -126,5 +128,5 @@ int mgag200_i2c_init(struct mga_device *
 	if (ret)
 		return ret;
 
-	return devm_add_action_or_reset(dev->dev, mgag200_i2c_release, i2c);
+	return drmm_add_action_or_reset(dev, mgag200_i2c_release, i2c);
 }


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

queue-6.1/drm-client-fix-null-pointer-dereference-in-drm_client_modeset_probe.patch
queue-6.1/drm-mgag200-bind-i2c-lifetime-to-drm-device.patch
queue-6.1/drm-mgag200-set-ddc-timeout-in-milliseconds.patch