Re: [PATCH v2 14/22] media: au0828 change to use Managed Media Controller API

Em Thu, 4 Feb 2016 08:05:00 -0200
Mauro Carvalho Chehab [off-list ref] escreveu:

Em Wed, 03 Feb 2016 21:03:46 -0700
Shuah Khan [off-list ref] escreveu:

quoted

Change au0828 to use Managed Media Controller API to
share media device and coordinate creating/deleting
the shared media device with the snd-usb-audio driver.
The shared media device is created as device resource
of the parent usb device of the two drivers.

Signed-off-by: Shuah Khan <redacted>
---
 drivers/media/usb/au0828/au0828-core.c | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/drivers/media/usb/au0828/au0828-core.c b/drivers/media/usb/au0828/au0828-core.c
index df2bc3f..b8c4bdd 100644
--- a/drivers/media/usb/au0828/au0828-core.c
+++ b/drivers/media/usb/au0828/au0828-core.c

@@ -134,10 +134,10 @@ static void au0828_unregister_media_device(struct au0828_dev *dev)
 {
 
 #ifdef CONFIG_MEDIA_CONTROLLER
-	if (dev->media_dev) {
+	if (dev->media_dev &&
+		media_devnode_is_registered(&dev->media_dev->devnode)) {
 		media_device_unregister(dev->media_dev);
 		media_device_cleanup(dev->media_dev);
-		kfree(dev->media_dev);
 		dev->media_dev = NULL;
 	}
 #endif

@@ -223,23 +223,24 @@ static int au0828_media_device_init(struct au0828_dev *dev,
 #ifdef CONFIG_MEDIA_CONTROLLER
 	struct media_device *mdev;
 
-	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
+	mdev = media_device_get_devres(&udev->dev);
 	if (!mdev)
 		return -ENOMEM;
 
-	mdev->dev = &udev->dev;
+	if (!media_devnode_is_registered(&mdev->devnode)) {
+		mdev->dev = &udev->dev;
 
-	if (!dev->board.name)
-		strlcpy(mdev->model, "unknown au0828", sizeof(mdev->model));
-	else
-		strlcpy(mdev->model, dev->board.name, sizeof(mdev->model));
-	if (udev->serial)
-		strlcpy(mdev->serial, udev->serial, sizeof(mdev->serial));
-	strcpy(mdev->bus_info, udev->devpath);
-	mdev->hw_revision = le16_to_cpu(udev->descriptor.bcdDevice);
-	mdev->driver_version = LINUX_VERSION_CODE;
+		if (udev->product)
+			strlcpy(mdev->model, udev->product,
+				sizeof(mdev->model));

Why did you change that? On some boards, udev->product doesn't reflect
the brand name, but have just some random generic data.

Also, as the other logs associated with the device uses dev->board.name,
we want the media controller to use the same name here. Ok, if this
is null, we could use udev->product as a replacement.

Ah, looking at patch 15/22, I understood why you wanted the above
change: if the device is registered first by ALSA, it won't have a
dev->board.name.

It looks OK to change from dev->board.name to udev->product then,
but please document the reason for it at the patch description.

Regards,
Mauro