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| author | Thomas Zimmermann <tzimmermann@suse.de> | 2022-05-16 15:43:37 +0200 |
|---|---|---|
| committer | Thomas Zimmermann <tzimmermann@suse.de> | 2022-05-17 20:23:19 +0200 |
| commit | 5913ab941d6ea782e841234c76958c6872ea752d (patch) | |
| tree | ea3024b603638befe2c26add0b3099bae47a5bd6 /drivers/gpu/drm/mgag200 | |
| parent | a77c2af0994e24ee36c7ffb6dc852770bdf06fb1 (diff) | |
| download | lwn-5913ab941d6ea782e841234c76958c6872ea752d.tar.gz lwn-5913ab941d6ea782e841234c76958c6872ea752d.zip | |
drm/mgag200: Acquire I/O lock while reading EDID
DDC operation conflicts with concurrent mode setting. Acquire the
driver's I/O lock in get_modes to prevent this. This change should
have been part of commit 931e3f3a0e99 ("drm/mgag200: Protect
concurrent access to I/O registers with lock"), but apparently got
lost somewhere.
v3:
* fix commit message to say 'drm/mgag200' (Jocelyn)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 931e3f3a0e99 ("drm/mgag200: Protect concurrent access to I/O registers with lock")
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Tested-by: Jocelyn Falempe <jfalempe@redhat.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Jocelyn Falempe <jfalempe@redhat.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Link: https://patchwork.freedesktop.org/patch/msgid/20220516134343.6085-2-tzimmermann@suse.de
Diffstat (limited to 'drivers/gpu/drm/mgag200')
| -rw-r--r-- | drivers/gpu/drm/mgag200/mgag200_mode.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c index 73d5a4a42b3a..762b9657ae8d 100644 --- a/drivers/gpu/drm/mgag200/mgag200_mode.c +++ b/drivers/gpu/drm/mgag200/mgag200_mode.c @@ -691,16 +691,26 @@ static void mgag200_disable_display(struct mga_device *mdev) static int mga_vga_get_modes(struct drm_connector *connector) { + struct mga_device *mdev = to_mga_device(connector->dev); struct mga_connector *mga_connector = to_mga_connector(connector); struct edid *edid; int ret = 0; + /* + * Protect access to I/O registers from concurrent modesetting + * by acquiring the I/O-register lock. + */ + mutex_lock(&mdev->rmmio_lock); + edid = drm_get_edid(connector, &mga_connector->i2c->adapter); if (edid) { drm_connector_update_edid_property(connector, edid); ret = drm_add_edid_modes(connector, edid); kfree(edid); } + + mutex_unlock(&mdev->rmmio_lock); + return ret; } |