[PATCH 02/10] drm/mgag200: Bind I2C lifetime to DRM device

Thomas Zimmermann tzimmermann at suse.de
Mon May 13 12:51:07 UTC 2024


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>
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+
---
 drivers/gpu/drm/mgag200/mgag200_i2c.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mgag200/mgag200_i2c.c b/drivers/gpu/drm/mgag200/mgag200_i2c.c
index 1029fef590f9b..4caeb68f3010c 100644
--- 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;
 
@@ -125,5 +127,5 @@ int mgag200_i2c_init(struct mga_device *mdev, struct mga_i2c_chan *i2c)
 	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);
 }
-- 
2.45.0



More information about the dri-devel mailing list