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 <[email protected]>
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
On Thu, Mar 12, 2020 at 04:55:52PM +0530, Syed Nayyar Waris wrote:
> 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 <[email protected]>
>
> 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.
> ---
Hello Syed,
Remove the review comments from the commit message and I think this
patch is all right. You can also extend the Fixes line so that it
doesn't wrap around. Add the following Signed-off-by line underneath
yours and it'll remind me that I've already reviewed this patch when you
submit v4 of your patchset:
Signed-off-by: William Breathitt Gray <[email protected]>
Thank you,
William Breathitt Gray
> 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
>