Re: [PATCH 0/2] fixes for adt7410

[Jonathan Cameron <jic23@kernel.org>]

On 7/16/2012 9:34 AM, Sascha Hauer wrote:
> On Sun, Jul 15, 2012 at 11:11:52PM +0200, Lars-Peter Clausen wrote:
>> On 07/15/2012 10:40 PM, Hartmut Knaack wrote:
>>> This patchset makes the ADT7410 usable. Main reason was the following error when trying to register one of these devices:
>>> [  180.945561] BUG: unable to handle kernel NULL pointer dereference at   (null)
>>> [  180.945592] IP: [<f84b1e80>] iio_device_register_eventset+0x380/0x3a0 [industrialio]
>>> This happens, since in industrialio-events.c __iio_add_event_config_attrs (which does a INIT_LIST_HEAD) is not called, if the channels attribute of the device is not set. As a result, list_for_each_entry causes those NULL pointer dereference problems. So, before trying to access those list elements, we check for their existence (also in unregister functions).
>>> Now the adt7410.c ended in some complex changes - my apologies for this:
>>>
>>>    * check for exact values provided through sysfs, otherwise output a verbose error/usage message for: sample mode, resolution, event mode
>>>    * adt7410_show_id: I don't see a point in masking out some LSBs, if they get shifted to oblivion, anyway -> no more need for ADT7410_MANUFACTORY_ID_MASK
>>>    * adt7410_convert_temperature: in 13 bit mode, the driver assumed the data to be stored in bits 0-12, but according to the data sheet, it is stored in bits 3-15. Temperature readings were always around 200(°C), while real temperature was something around 20(°C). Simple fix: mask out bits 0-2 in 13 bit mode and use the 16 bit routines from that point on.
>>>    * adt7410_set_t_bound: handle float values provided through sysfs properly. Also, simplify treatment of 13 bit values by masking out bits 0-2.
>>>    * adt7410_probe, adt7410_remove: fix another possible NULL pointer dereference issue, in case no platform data is provided. Sync chip->config with the config register
>>
>> Hi,
>>
>> Sascha Hauer posted a couple of patches a while ago which seem to fix a
>> similar set of issues.
>>
>> See: http://www.spinics.net/lists/linux-iio/msg05947.html and
>> http://www.spinics.net/lists/linux-iio/msg05955.html
>
> Indeed, most if not all of the mentioned issues should be fixed already
> with these patches.
>
Just to reiterate what I said to Sascha at the time...  This driver does
not belong in IIO. It is very much a hardware monitoring part and so
wants to move to hwmon. We aren't going to take it out of staging into
drivers/iio and I'm rather unwilling to take any 'new' features into the
staging version. Someone with hardware who is interesting needs to bite
the bullet and convert / rewrite this driver as a hwmon device.