60965c6a19
When the adap_enable callback is called the adap->lock is held. When disabling the adapter it attempts to stop the kthread that deals with receiving and transmitting messages. However, kthread_stop waits for the thread to stop, so all that time adap->lock is held. Unfortunately, the kernel thread itself can call functions that take that same lock, so a deadlock can occur. Change the logic to keep the kernel thread running and instead when disabling the adapter, just set the pin to high, go to idle and then to state OFF and disable the interrupt. Only stop the kernel thread when the adapter is deleted. This way disabling the adapter will not wait for anything and the deadlock is avoided. Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.