b1af7528d2
When an alternate driver (vfio-ap) has bound an ap queue and this binding is revised the ap queue device is in an intermittent state not bound to any driver. The internal state variable covered this with the state AP_STATE_BORKED which is also used to reflect broken devices. When now an ap bus scan runs such a device is destroyed and on the next scan reconstructed. So a stress test with high frequency switching the queue driver between the default and the vfio-ap driver hit this gap and the queue was removed until the next ap bus scan. This fix now introduces another state for the in-between condition for a queue momentary not bound to a driver and so the ap bus scan function skips this device instead of removing it. Also some very slight but maybe helpful debug feature messages come with this patch - in particular a message showing that a broken card/queue device will get removed. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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.