7b942b4be9
For rolling back after an error, qdio_establish() calls qdio_shutdown().
If the error occurs early enough, then the qdio_irq's state still is
QDIO_IRQ_STATE_INACTIVE and qdio_shutdown() does nothing.
But at _any_ point where qdio_establish() bails out in this way,
qdio_setup_irq() will have already replaced the IRQ handler. This then
won't be restored after an early error, and the device can end up being
returned to the device driver with qdio's IRQ handler still installed.
Slightly reorder qdio_setup_irq() so we can be 100% sure that the IRQ
handler was replaced. Then fix the bug in qdio_establish() by calling a
helper that rolls back only the IRQ handler modification.
Also use the new helper in qdio_shutdown() to keep things in sync, and
slightly clean up the locking while doing so.
This makes minor semantical changes, but holding setup_mutex gives us
sufficient leeway to eg. pull qdio_shutdown_thinint() outside of the
ccwdev lock's scope.
Fixes: 779e6e1c724d ("[S390] qdio: new qdio driver.")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.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.