From: Syed Nayyar Waris syednwaris@gmail.com
[ Upstream commit d5ed76adb926a90fada98f518abc1ab6ef07d28f ]
Add lock protection from race conditions to the 104-quad-8 counter driver for filter clock prescaler code changes. Mutex calls used for protection.
Signed-off-by: Syed Nayyar Waris syednwaris@gmail.com Fixes: de65d0556343 ("counter: 104-quad-8: Support Filter Clock Prescaler") Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/counter/104-quad-8.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c index 9364dc188f8ff..d22cfae1b0198 100644 --- a/drivers/counter/104-quad-8.c +++ b/drivers/counter/104-quad-8.c @@ -1365,6 +1365,8 @@ static ssize_t quad8_signal_fck_prescaler_write(struct counter_device *counter, if (ret) return ret;
+ mutex_lock(&priv->lock); + priv->fck_prescaler[channel_id] = prescaler;
/* Reset Byte Pointer */ @@ -1375,6 +1377,8 @@ static ssize_t quad8_signal_fck_prescaler_write(struct counter_device *counter, outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_PRESET_PSC, base_offset + 1);
+ mutex_unlock(&priv->lock); + return len; }