[PATCH v5 3/3] counter: 104-quad-8: Add lock guards - filter clock prescaler

[PATCH v5 3/3] counter: 104-quad-8: Add lock guards - filter clock prescaler

[Syed Nayyar Waris]

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>
---
Changes in v5:
 - Change spin lock calls to mutex lock calls.
 - Modify the title description.

 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..b268165 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;
 
+	mutex_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);
 
+	mutex_unlock(&priv->lock);
+
 	return len;
 }
 
-- 
2.7.4

Re: [PATCH v5 3/3] counter: 104-quad-8: Add lock guards - filter clock prescaler

[William Breathitt Gray]

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On Mon, Mar 16, 2020 at 06:20:46PM +0530, Syed Nayyar Waris wrote:
> 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>
> ---
> Changes in v5:
>  - Change spin lock calls to mutex lock calls.
>  - Modify the title description.

Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>

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Re: [PATCH v5 3/3] counter: 104-quad-8: Add lock guards - filter clock prescaler

[Syed Nayyar Waris]

On Wed, Mar 18, 2020 at 7:48 AM William Breathitt Gray
<vilhelm.gray@gmail.com> wrote:
>
> On Mon, Mar 16, 2020 at 06:20:46PM +0530, Syed Nayyar Waris wrote:
> > 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>
> > ---
> > Changes in v5:
> >  - Change spin lock calls to mutex lock calls.
> >  - Modify the title description.
>
> Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>

Adding the 'Fixes' tag:

Fixes: 9b74dddf79be ("counter: 104-quad-8: Support Filter Clock Prescaler")

Regards
Syed Nayyar Waris

Re: [PATCH v5 3/3] counter: 104-quad-8: Add lock guards - filter clock prescaler

[Jonathan Cameron]

On Sun, 7 Jun 2020 10:55:08 +0530
Syed Nayyar Waris <syednwaris@gmail.com> wrote:

> On Wed, Mar 18, 2020 at 7:48 AM William Breathitt Gray
> <vilhelm.gray@gmail.com> wrote:
> >
> > On Mon, Mar 16, 2020 at 06:20:46PM +0530, Syed Nayyar Waris wrote:  
> > > 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>
> > > ---
> > > Changes in v5:
> > >  - Change spin lock calls to mutex lock calls.
> > >  - Modify the title description.  
> >
> > Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>  
> 
> Adding the 'Fixes' tag:
> 
> Fixes: 9b74dddf79be ("counter: 104-quad-8: Support Filter Clock Prescaler")
Replace hash with upstream one and applied to the fixes-togreg branch of iio.git
Thanks,

Jonathan

> 
> Regards
> Syed Nayyar Waris