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c32b53f965
Current driver may meet reconfigure failure caused by below reasons: 1. The wdog on iMX7ULP has different behavior after RCS valid. It needs to wait more than 2.5 wdog clock for clock sync before next reconfiguration, while imx8ulp wdog does not need such delay. 2. After unlock, there is 128 bus clock window opened for reconfiguration, but on iMX8ULP, the HW can't guarantee the latency. So it is possible the window is closed before the writing arrives to wdog. 3. If the PRES is enabled, the RCS valid time becomes x256 to the time of PRES disabled. It is about 1715ms on iMX8ULP. So We have to increase the RCS timeout and can't wait it in IRQ disabled. The patch updates the driver to handle failures 1. Using different wait for unlock and RCS. Unlock valid time is very short and only related to bus clock. It must be in IRQ disabled to avoid being interrupted in 128 clock window. But for RCS time, it is longer and ok for IRQ enabled. 2. Add retry for any reconfigure failure with default 5 times. 3. Add "fsl,imx8ulp-wdt" compatile string for iMX8ULP and afterwards platform which don't need more 2.5 wdog clock after RCS valid. For imx7ulp, add post delay of 2.5 clock after RCS valid. Signed-off-by: Ye Li <ye.li@nxp.com> Signed-off-by: Alice Guo <alice.guo@nxp.com> Reviewed-by: Jacky Bai <ping.bai@nxp.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20220825083256.14565-6-alice.guo@oss.nxp.com Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.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.