5d4f78564c
The RX buffer pool is allocated in qeth_alloc_qdio_queues().
A subsequent pool resizing is then handled in a very simple way:
first free the current pool, then allocate a new pool of the requested
size.
There's two ways where this can go wrong:
1. if the resize action happens _before_ the initial pool was allocated,
then a subsequent initialization will call qeth_alloc_qdio_queues()
and fill the pool with a second(!) set of pages. We consume twice the
planned amount of memory.
This is easy to fix - just skip the resizing if the queues haven't
been allocated yet.
2. if the initial pool was created by qeth_alloc_qdio_queues() but a
subsequent resizing fails, then the device has no(!) RX buffer pool.
The next initialization will _not_ call qeth_alloc_qdio_queues(), and
attempting to back the RX buffers with pages in
qeth_init_qdio_queues() will fail.
Not very difficult to fix either - instead of re-allocating the whole
pool, just allocate/free as many entries to match the desired size.
Fixes: 4a71df50047f ("qeth: new qeth device driver")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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.