From d5ed76adb926a90fada98f518abc1ab6ef07d28f Mon Sep 17 00:00:00 2001 From: Syed Nayyar Waris Date: Mon, 16 Mar 2020 18:20:46 +0530 Subject: [PATCH] counter: 104-quad-8: Add lock guards - filter clock prescaler 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 Fixes: de65d0556343 ("counter: 104-quad-8: Support Filter Clock Prescaler") Signed-off-by: Jonathan Cameron --- 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 9364dc188f8f..d22cfae1b019 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; } -- 2.25.1