The notify routines may sleep. So, they can't be called in spinlock
context. Also, they may want to call other media routines that might
be spinning the spinlock, like creating a link.
This fixes the following bug:
[ 1839.510587] BUG: sleeping function called from invalid context at mm/slub.c:1289
[ 1839.510881] in_atomic(): 1, irqs_disabled(): 0, pid: 3479, name: modprobe
[ 1839.511157] 4 locks held by modprobe/3479:
[ 1839.511415] #0: (&dev->mutex){......}, at: [<ffffffff81ce8933>] __driver_attach+0xa3/0x160
[ 1839.512381] #1: (&dev->mutex){......}, at: [<ffffffff81ce8941>] __driver_attach+0xb1/0x160
[ 1839.512388] #2: (register_mutex#5){+.+.+.}, at: [<ffffffffa10596c7>] usb_audio_probe+0x257/0x1c90 [snd_usb_audio]
[ 1839.512401] #3: (&(&mdev->lock)->rlock){+.+.+.}, at: [<ffffffffa0e6051b>] media_device_register_entity+0x1cb/0x700 [media]
[ 1839.512412] CPU: 2 PID: 3479 Comm: modprobe Not tainted 4.5.0-rc3+ #49
[ 1839.512415] Hardware name: /NUC5i7RYB, BIOS RYBDWi35.86A.0350.2015.0812.1722 08/12/2015
[ 1839.512417] 0000000000000000 ffff8803b3f6f288 ffffffff81933901 ffff8803c4bae000
[ 1839.512422] ffff8803c4bae5c8 ffff8803b3f6f2b0 ffffffff811c6af5 ffff8803c4bae000
[ 1839.512427] ffffffff8285d7f6 0000000000000509 ffff8803b3f6f2f0 ffffffff811c6ce5
[ 1839.512432] Call Trace:
[ 1839.512436] [<ffffffff81933901>] dump_stack+0x85/0xc4
[ 1839.512440] [<ffffffff811c6af5>] ___might_sleep+0x245/0x3a0
[ 1839.512443] [<ffffffff811c6ce5>] __might_sleep+0x95/0x1a0
[ 1839.512446] [<ffffffff8155aade>] kmem_cache_alloc_trace+0x20e/0x300
[ 1839.512451] [<ffffffffa0e66e3d>] ? media_add_link+0x4d/0x140 [media]
[ 1839.512455] [<ffffffffa0e66e3d>] media_add_link+0x4d/0x140 [media]
[ 1839.512459] [<ffffffffa0e69931>] media_create_pad_link+0xa1/0x600 [media]
[ 1839.512463] [<ffffffffa0fe11b3>] au0828_media_graph_notify+0x173/0x360 [au0828]
[ 1839.512467] [<ffffffffa0e68a6a>] ? media_gobj_create+0x1ba/0x480 [media]
[ 1839.512471] [<ffffffffa0e606fb>] media_device_register_entity+0x3ab/0x700 [media]
Tested with an HVR-950Q, under the following testcases:
1) load au0828 driver first, and then snd-usb-audio;
2) load snd-usb-audio driver first, and then au0828;
3) loading both drivers, and then connecting the device.
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
---
drivers/media/i2c/tvp5150.c | 39 ++++++++++++++++++++++-------------
drivers/media/media-device.c | 5 +++--
drivers/media/v4l2-core/v4l2-common.c | 8 +++++++
include/media/v4l2-subdev.h | 4 ++++
4 files changed, 40 insertions(+), 16 deletions(-)
diff --git a/drivers/media/i2c/tvp5150.c b/drivers/media/i2c/tvp5150.c
index ff18444e19e4..14004fd7d0fb 100644
--- a/drivers/media/i2c/tvp5150.c
+++ b/drivers/media/i2c/tvp5150.c
@@ -1208,6 +1208,28 @@ static int tvp5150_registered_async(struct v4l2_subdev *sd)
return 0;
}
+static int __maybe_unused tvp5150_pad_init(struct v4l2_subdev *sd)
+{
+ struct tvp5150 *core = to_tvp5150(sd);
+ int res;
+
+#if defined(CONFIG_MEDIA_CONTROLLER)
+ core->pads[DEMOD_PAD_IF_INPUT].flags = MEDIA_PAD_FL_SINK;
+ core->pads[DEMOD_PAD_VID_OUT].flags = MEDIA_PAD_FL_SOURCE;
+ core->pads[DEMOD_PAD_VBI_OUT].flags = MEDIA_PAD_FL_SOURCE;
+
+ sd->entity.function = MEDIA_ENT_F_ATV_DECODER;
+
+ res = media_entity_pads_init(&sd->entity, DEMOD_NUM_PADS, core->pads);
+ if (res < 0)
+ return res;
+
+ sd->entity.ops = &tvp5150_sd_media_ops;
+#endif
+ return 0;
+}
+
+
/* ----------------------------------------------------------------------- */
static const struct v4l2_ctrl_ops tvp5150_ctrl_ops = {
@@ -1246,6 +1268,9 @@ static const struct v4l2_subdev_vbi_ops tvp5150_vbi_ops = {
};
static const struct v4l2_subdev_pad_ops tvp5150_pad_ops = {
+#ifdef CONFIG_MEDIA_CONTROLLER
+ .pad_init = tvp5150_pad_init,
+#endif
.enum_mbus_code = tvp5150_enum_mbus_code,
.enum_frame_size = tvp5150_enum_frame_size,
.set_fmt = tvp5150_fill_fmt,
@@ -1475,20 +1500,6 @@ static int tvp5150_probe(struct i2c_client *c,
v4l2_i2c_subdev_init(sd, c, &tvp5150_ops);
sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
-#if defined(CONFIG_MEDIA_CONTROLLER)
- core->pads[DEMOD_PAD_IF_INPUT].flags = MEDIA_PAD_FL_SINK;
- core->pads[DEMOD_PAD_VID_OUT].flags = MEDIA_PAD_FL_SOURCE;
- core->pads[DEMOD_PAD_VBI_OUT].flags = MEDIA_PAD_FL_SOURCE;
-
- sd->entity.function = MEDIA_ENT_F_ATV_DECODER;
-
- res = media_entity_pads_init(&sd->entity, DEMOD_NUM_PADS, core->pads);
- if (res < 0)
- return res;
-
- sd->entity.ops = &tvp5150_sd_media_ops;
-#endif
-
res = tvp5150_detect_version(core);
if (res < 0)
return res;
diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
index 6ba6e8f982fc..fc3c199e5500 100644
--- a/drivers/media/media-device.c
+++ b/drivers/media/media-device.c
@@ -587,14 +587,15 @@ int __must_check media_device_register_entity(struct media_device *mdev,
media_gobj_create(mdev, MEDIA_GRAPH_PAD,
&entity->pads[i].graph_obj);
+ spin_unlock(&mdev->lock);
+
/* invoke entity_notify callbacks */
list_for_each_entry_safe(notify, next, &mdev->entity_notify, list) {
(notify)->notify(entity, notify->notify_data);
}
- spin_unlock(&mdev->lock);
-
mutex_lock(&mdev->graph_mutex);
+
if (mdev->entity_internal_idx_max
>= mdev->pm_count_walk.ent_enum.idx_max) {
struct media_entity_graph new = { .top = 0 };
diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
index 5b808500e7e7..6bcdf557e027 100644
--- a/drivers/media/v4l2-core/v4l2-common.c
+++ b/drivers/media/v4l2-core/v4l2-common.c
@@ -112,6 +112,14 @@ EXPORT_SYMBOL(v4l2_ctrl_query_fill);
void v4l2_i2c_subdev_init(struct v4l2_subdev *sd, struct i2c_client *client,
const struct v4l2_subdev_ops *ops)
{
+ /*
+ * Initialize the MC pads - for now, this will be called
+ * unconditionally, since the current implementation will defer
+ * the pads initialization until the media_dev is created.
+ */
+ if (v4l2_subdev_has_op(sd, pad, pad_init))
+ sd->ops->pad->pad_init(sd);
+
v4l2_subdev_init(sd, ops);
sd->flags |= V4L2_SUBDEV_FL_IS_I2C;
/* the owner is the same as the i2c_client's driver owner */
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index 11e2dfec0198..c9bb221029e4 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -572,6 +572,9 @@ struct v4l2_subdev_pad_config {
/**
* struct v4l2_subdev_pad_ops - v4l2-subdev pad level operations
*
+ * @pad_init: callback that initializes the media-controller specific part
+ * of the subdev driver, creating its pads
+ *
* @enum_mbus_code: callback for VIDIOC_SUBDEV_ENUM_MBUS_CODE ioctl handler
* code.
* @enum_frame_size: callback for VIDIOC_SUBDEV_ENUM_FRAME_SIZE ioctl handler
@@ -607,6 +610,7 @@ struct v4l2_subdev_pad_config {
* may be adjusted by the subdev driver to device capabilities.
*/
struct v4l2_subdev_pad_ops {
+ int (*pad_init)(struct v4l2_subdev *sd);
int (*enum_mbus_code)(struct v4l2_subdev *sd,
struct v4l2_subdev_pad_config *cfg,
struct v4l2_subdev_mbus_code_enum *code);
--
2.5.0
--
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