Messages in this thread Patch in this message | | | Date | Thu, 12 Mar 2020 16:55:52 +0530 | From | Syed Nayyar Waris <> | Subject | [PATCH v3 3/3] counter: 104-quad-8: Add lock guards for filter clock prescaler |
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Add lock protection from race conditions in the 104-quad-8 counter driver for filter clock prescaler related changes. There is no IRQ handling so used spin_lock calls for protection.
Fixes: 9b74dddf79be ("counter: 104-quad-8: Support Filter Clock Prescaler")
Signed-off-by: Syed Nayyar Waris <syednwaris@gmail.com>
Split the patch from generic interface and differential encoder cable status changes. Also, include more code statements for protection using spin_lock calls and remove protection from few code statements which are unnecessary. --- 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 9dab190..58615e4 100644 --- a/drivers/counter/104-quad-8.c +++ b/drivers/counter/104-quad-8.c @@ -1230,6 +1230,8 @@ static ssize_t quad8_signal_fck_prescaler_write(struct counter_device *counter, if (ret) return ret; + spin_lock(&priv->lock); + priv->fck_prescaler[channel_id] = prescaler; /* Reset Byte Pointer */ @@ -1240,6 +1242,8 @@ 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); + spin_unlock(&priv->lock); + return len; } -- 2.7.4
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