On Mon, 14 Mar 2016 11:13:58 +0100, Mauro Carvalho Chehab wrote:
Em Mon, 14 Mar 2016 09:22:37 +0200 Sakari Ailus sakari.ailus@iki.fi escreveu:
Hi Shuah,
On Sat, Mar 12, 2016 at 06:48:09PM -0700, Shuah Khan wrote:
Add GFP flags to media_create_pad_link(), media_create_intf_link(), media_devnode_create(), and media_add_link() that could get called in atomic context to allow callers to pass in the right flags for memory allocation.
tree-wide driver changes for media_*() GFP flags change: Change drivers to add gfpflags to interffaces, media_create_pad_link(), media_create_intf_link() and media_devnode_create().
Signed-off-by: Shuah Khan shuahkh@osg.samsung.com Suggested-by: Mauro Carvalho Chehab mchehab@osg.samsung.com
What's the use case for calling the above functions in an atomic context?
ALSA code seems to do a lot of stuff at atomic context. That's what happens on my test machine when au0828 gets probed before snd-usb-audio: http://pastebin.com/LEX5LD5K
It seems that ALSA USB probe routine (usb_audio_probe) happens in atomic context.
No, usb_audio_probe() doesn't take a lock. But media_device_register_entity() seems taking a spinlock, instead.
Takashi