stable inclusion
from stable-5.10.51
commit 5a5ebf5d48229b4d227dae8b5eeef996bfce20b6
bugzilla: 175263 https://gitee.com/openeuler/kernel/issues/I4DT6F

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=5a5ebf5d48229b4d227dae8b5eeef996bfce20b6

--------------------------------

commit 8b33dfe0 upstream.

Bad counter reads are experienced sometimes when bit 10 or greater rolls
over. Originally, testing showed that at least 10 lower bits would be
set to the same value during these bad reads. However, some users still
reported time skips.

Wider testing revealed that on some chips, occasionally only the lowest
9 bits would read as the anomalous value. During these reads (which
still happen only when bit 10), bit 9 would read as the correct value.

Reduce the mask by one bit to cover these cases as well.

Cc: stable@vger.kernel.org
Fixes: c950ca8c ("clocksource/drivers/arch_timer: Workaround for Allwinner A64 timer instability")
Reported-by: NRoman Stratiienko <r.stratiienko@gmail.com>
Signed-off-by: NSamuel Holland <samuel@sholland.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210515021439.55316-1-samuel@sholland.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>