counter: stm32-timer-cnt: fix ceiling write max value
authorFabrice Gasnier <fabrice.gasnier@foss.st.com>
Tue, 2 Mar 2021 14:43:55 +0000 (15:43 +0100)
committerJonathan Cameron <Jonathan.Cameron@huawei.com>
Sat, 6 Mar 2021 16:47:03 +0000 (16:47 +0000)
commite4c3e133294c0a292d21073899b05ebf530169bd
treeb1929940b125ccc62167296cd29e58c795710285
parentfae6f62e6a580b663ecf42c2120a0898deae9137
counter: stm32-timer-cnt: fix ceiling write max value

The ceiling value isn't checked before writing it into registers. The user
could write a value higher than the counter resolution (e.g. 16 or 32 bits
indicated by max_arr). This makes most significant bits to be truncated.
Fix it by checking the max_arr to report a range error [1] to the user.

[1] https://lkml.org/lkml/2021/2/12/358

Fixes: ad29937e206f ("counter: Add STM32 Timer quadrature encoder")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1614696235-24088-1-git-send-email-fabrice.gasnier@foss.st.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
drivers/counter/stm32-timer-cnt.c