* [PATCH v2 3/7] iio: adc: ad7793: claim direct mode when writing frequency
@ 2016-06-02 4:28 Alison Schofield
2016-06-02 8:37 ` Lars-Peter Clausen
0 siblings, 1 reply; 3+ messages in thread
From: Alison Schofield @ 2016-06-02 4:28 UTC (permalink / raw)
To: jic23; +Cc: lars, Michael.Hennerich, knaack.h, pmeerw, linux-iio, linux-kernel
Driver was checking for direct mode and trying to lock it, but
left a gap where mode could change before the desired operation.
Use iio_device_claim_direct_mode() to guarantee device stays in
direct mode.
Refactor function to clarify look-up followed by lock sequence.
Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Cc: Daniel Baluta <daniel.baluta@gmail.com>
---
Changes in v2
Refactored function per reviewers comments
Updated changelog
drivers/iio/adc/ad7793.c | 32 +++++++++++++-------------------
1 file changed, 13 insertions(+), 19 deletions(-)
diff --git a/drivers/iio/adc/ad7793.c b/drivers/iio/adc/ad7793.c
index 7b07bb6..a43722f 100644
--- a/drivers/iio/adc/ad7793.c
+++ b/drivers/iio/adc/ad7793.c
@@ -369,13 +369,6 @@ static ssize_t ad7793_write_frequency(struct device *dev,
long lval;
int i, ret;
- mutex_lock(&indio_dev->mlock);
- if (iio_buffer_enabled(indio_dev)) {
- mutex_unlock(&indio_dev->mlock);
- return -EBUSY;
- }
- mutex_unlock(&indio_dev->mlock);
-
ret = kstrtol(buf, 10, &lval);
if (ret)
return ret;
@@ -383,20 +376,21 @@ static ssize_t ad7793_write_frequency(struct device *dev,
if (lval == 0)
return -EINVAL;
- ret = -EINVAL;
-
for (i = 0; i < 16; i++)
- if (lval == st->chip_info->sample_freq_avail[i]) {
- mutex_lock(&indio_dev->mlock);
- st->mode &= ~AD7793_MODE_RATE(-1);
- st->mode |= AD7793_MODE_RATE(i);
- ad_sd_write_reg(&st->sd, AD7793_REG_MODE,
- sizeof(st->mode), st->mode);
- mutex_unlock(&indio_dev->mlock);
- ret = 0;
- }
+ if (lval == st->chip_info->sample_freq_avail[i])
+ break;
+ if (i == 16)
+ return -EINVAL;
- return ret ? ret : len;
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+ st->mode &= ~AD7793_MODE_RATE(-1);
+ st->mode |= AD7793_MODE_RATE(i);
+ ad_sd_write_reg(&st->sd, AD7793_REG_MODE, sizeof(st->mode), st->mode);
+ iio_device_release_direct_mode(indio_dev);
+
+ return len;
}
static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO,
--
2.1.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2 3/7] iio: adc: ad7793: claim direct mode when writing frequency
2016-06-02 4:28 [PATCH v2 3/7] iio: adc: ad7793: claim direct mode when writing frequency Alison Schofield
@ 2016-06-02 8:37 ` Lars-Peter Clausen
2016-06-03 12:01 ` Jonathan Cameron
0 siblings, 1 reply; 3+ messages in thread
From: Lars-Peter Clausen @ 2016-06-02 8:37 UTC (permalink / raw)
To: Alison Schofield, jic23
Cc: Michael.Hennerich, knaack.h, pmeerw, linux-iio, linux-kernel
On 06/02/2016 06:28 AM, Alison Schofield wrote:
> Driver was checking for direct mode and trying to lock it, but
> left a gap where mode could change before the desired operation.
> Use iio_device_claim_direct_mode() to guarantee device stays in
> direct mode.
>
> Refactor function to clarify look-up followed by lock sequence.
>
> Signed-off-by: Alison Schofield <amsfield22@gmail.com>
> Cc: Daniel Baluta <daniel.baluta@gmail.com>
Looks good, thanks.
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2 3/7] iio: adc: ad7793: claim direct mode when writing frequency
2016-06-02 8:37 ` Lars-Peter Clausen
@ 2016-06-03 12:01 ` Jonathan Cameron
0 siblings, 0 replies; 3+ messages in thread
From: Jonathan Cameron @ 2016-06-03 12:01 UTC (permalink / raw)
To: Lars-Peter Clausen, Alison Schofield
Cc: Michael.Hennerich, knaack.h, pmeerw, linux-iio, linux-kernel
On 02/06/16 09:37, Lars-Peter Clausen wrote:
> On 06/02/2016 06:28 AM, Alison Schofield wrote:
>> Driver was checking for direct mode and trying to lock it, but
>> left a gap where mode could change before the desired operation.
>> Use iio_device_claim_direct_mode() to guarantee device stays in
>> direct mode.
>>
>> Refactor function to clarify look-up followed by lock sequence.
>>
>> Signed-off-by: Alison Schofield <amsfield22@gmail.com>
>> Cc: Daniel Baluta <daniel.baluta@gmail.com>
>
> Looks good, thanks.
>
> Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Applied to the togreg branch of iio.git - initially pushed out as
testing for the autobuilders to play with it.
Thanks,
Jonathan
> --
> To unsubscribe from this list: send the line "unsubscribe linux-iio" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2016-06-03 12:02 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-06-02 4:28 [PATCH v2 3/7] iio: adc: ad7793: claim direct mode when writing frequency Alison Schofield
2016-06-02 8:37 ` Lars-Peter Clausen
2016-06-03 12:01 ` Jonathan Cameron
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).