Commit Graph

4 Commits

Author SHA1 Message Date
Hans Verkuil
ae505d7113 cec: race fix: don't return -ENONET in cec_receive()
commit b94aac64a4 upstream.

When calling CEC_RECEIVE do not check if the adapter is configured.
Typically CEC_RECEIVE is called after a select() and if that indicates
that there are messages in the receive queue, then you should always be
able to dequeue a message.

The race condition here is that a message has been received and is
queued, so select() tells userspace that a message is available. But
before the application calls CEC_RECEIVE the adapter is unconfigured
(e.g. the HDMI cable is removed). Now select will always report that
there is a message, but calling CEC_RECEIVE will always return -ENONET
because the adapter is no longer configured and so will never actually
dequeue the message.

There is really no need for this check, and in fact the ENONET error
code was never documented for CEC_RECEIVE. This may have been a left-over
of old code that was never updated.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-24 07:06:14 +02:00
Hans Verkuil
f51e80804f [media] cec: pass parent device in register(), not allocate()
The cec_allocate_adapter function doesn't need the parent device, only the
cec_register_adapter function needs it.

Drop the cec_devnode parent field, since devnode.dev.parent can be used
instead.

This change makes the framework consistent with other frameworks where the
parent device is not used until the device is registered.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-11-29 12:07:17 -02:00
Hans Verkuil
7ae2a888ee [media] cec: sanitize msg.flags
The CEC_MSG_FL_REPLY_TO_FOLLOWERS message flag only makes sense for transmitted
messages where you want to wait for the reply.

Clear the flag in all other cases.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-11-16 15:42:03 -02:00
Hans Verkuil
0dbacebede [media] cec: move the CEC framework out of staging and to media
The last open issues have been addressed, so it is time to move
this out of staging and into the mainline and to move the public
cec headers to include/uapi/linux.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-11-16 15:40:20 -02:00