01365633bd
The main arcnet interrupt handler calls arcnet_close() then
arcnet_open(), if the RESET status flag is encountered.
This is invalid:
1) In general, interrupt handlers should never call ->ndo_stop() and
->ndo_open() functions. They are usually full of blocking calls and
other methods that are expected to be called only from drivers
init and exit code paths.
2) arcnet_close() contains a del_timer_sync(). If the irq handler
interrupts the to-be-deleted timer, del_timer_sync() will just loop
forever.
3) arcnet_close() also calls tasklet_kill(), which has a warning if
called from irq context.
4) For device reset, the sequence "arcnet_close(); arcnet_open();" is
not complete. Some children arcnet drivers have special init/exit
code sequences, which then embed a call to arcnet_open() and
arcnet_close() accordingly. Check drivers/net/arcnet/com20020.c.
Run the device RESET sequence from a scheduled workqueue instead.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20210128194802.727770-1-a.darwish@linutronix.de
Signed-off-by: Jakub Kicinski <kuba@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.