Lars-Peter Clausen <lars@xxxxxxxxxx> wrote:
>On 11/09/2013 01:34 PM, Jonathan Cameron wrote:
>> On 10/24/13 12:50, Jonathan Cameron wrote:
>>> On 10/24/13 11:44, Lars-Peter Clausen wrote:
>>>> On 10/24/2013 12:34 PM, Sebastian Andrzej Siewior wrote:
>>>>> On 10/24/2013 11:41 AM, Lars-Peter Clausen wrote:
>>>>>> The driver seems to be missing the iio_buffer_attach() call.
>Something like
>>>>>> this should fix the problem:
>>>>>>
>>>>>> diff --git a/drivers/iio/adc/ti_am335x_adc.c
>b/drivers/iio/adc/ti_am335x_adc.c
>>>>>> index ef54d8a..bf9c89c 100644
>>>>>> --- a/drivers/iio/adc/ti_am335x_adc.c
>>>>>> +++ b/drivers/iio/adc/ti_am335x_adc.c
>>>>>> @@ -229,12 +229,15 @@ static int
>tiadc_iio_buffered_hardware_setup(struct
>>>>>> iio_dev *indio_dev,
>>>>>> unsigned long flags,
>>>>>> const struct iio_buffer_setup_ops *setup_ops)
>>>>>> {
>>>>>> + struct iio_buffer *buffer;
>>>>>> int ret;
>>>>>>
>>>>>> - indio_dev->buffer = iio_kfifo_allocate(indio_dev);
>>>>>> - if (!indio_dev->buffer)
>>>>>> + buffer = iio_kfifo_allocate(indio_dev);
>>>>>> + if (!buffer)
>>>>>> return -ENOMEM;
>>>>>>
>>>>>> + iio_device_attach_buffer(indio_dev, buffer);
>>>>>> +
>>>>>> ret = request_threaded_irq(irq, pollfunc_th, pollfunc_bh,
>>>>>> flags, indio_dev->name, indio_dev);
>>>>>> if (ret)
>>>>>
>>>>> Yep, that works, thanks.
>>>>>
>>>>> Shouldn't the two
>>>>>
>>>>> tiadc_iio_buffered_hardware_remove(indio_dev);
>>>>> tiadc_channels_remove(indio_dev);
>>>>>
>>>>> in tiadc_remove() be reversed in their call order? The second
>alter is
>>>>> accessing the buffer which is released by the former one.
>>>>>
>>>>
>>>> As far as I can see tiadc_channels_remove() only does a
>>>> kfree(indio_dev->channels), so it does not access the buffer at
>all.
>>> Certainly seems to be true...
>>>>
>>>>> btw: is all this ref counting really required? I mean I would
>assume
>>>>> allocate buffer in one place (at probe time) release it remove
>time
>>>>> should be enough.
>>>>
>>>> It is required. Userspace may still be reading from the buffer when
>the
>>>> driver frees it. So we need proper refcounting here.
>>>
>>> Lars, can you do a clean version of the above with a reported-by
>from Sebastian
>>> then Sebastian can you ack (if you are happy with it of course!)
>>>
>> Lars, I've turned the above into a coherent patch and applied it to
>the fixes-togreg
>> branch. I've added your Signed-off-by: Shout if you would prefer
>not.
>>
>> Also a reported by for Sebastian.
>>
>> I didn't want this patch to fall through the cracks given it's been
>around a while now.
>
>It was still on my radar. The plan was to send it once the merge window
>has
>closed.
Fair enough. I just got impatient :)
>
>- Lars
--
Sent from my Android phone with K-9 Mail. Please excuse my brevity.
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
