8dbd6e4ce1
The watchdog timer is used to monitor whether the process
of transmitting data is timeout. If we use qlcnic driver,
the dev_watchdog() that is the timer handler of watchdog
timer will call qlcnic_tx_timeout() to process the timeout.
But the qlcnic_tx_timeout() calls msleep(), as a result,
the sleep-in-atomic-context bugs will happen. The processes
are shown below:
(atomic context)
dev_watchdog
qlcnic_tx_timeout
qlcnic_83xx_idc_request_reset
qlcnic_83xx_lock_driver
msleep
---------------------------
(atomic context)
dev_watchdog
qlcnic_tx_timeout
qlcnic_83xx_idc_request_reset
qlcnic_83xx_lock_driver
qlcnic_83xx_recover_driver_lock
msleep
Fix by changing msleep() to mdelay(), the mdelay() is
busy-waiting and the bugs could be mitigated.
Fixes: 629263acaea3 ("qlcnic: 83xx CNA inter driver communication mechanism")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
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.