Re: [PATCH v4 1/1] iio:pressure: initial zpa2326 barometer support

On 13.09.2016 08:55, Gregor Boirie wrote:

Hi,

On 09/10/2016 05:37 PM, Jonathan Cameron wrote:

quoted

On 09/09/16 16:01, Gregor Boirie wrote:

quoted

Introduce driver for Murata ZPA2326 pressure and temperature sensor:
http://www.murata.com/en-us/products/productdetail?partno=ZPA2326-0311A-R

Signed-off-by: Gregor Boirie <gregor.boirie-ITF29qwbsa/QT0dZR+AlfA@public.gmane.org>

This looks pretty good to me now.  A few minor bits and bobs inline.

I almost took it as is, but would like to have it sit on the list
in it's current form for a few more days anyway so might as well get
these few corners tidied up!

[...]

quoted

+/*
+ * Debugfs stuff
+ *
+ * We want to prevent debugfs hooks from altering configuration while 
chip
+ * sampling is ongoing to preserve data consistency. Moreover, a few 
registers,
+ * when read, change hardware state, e.g. interrupt acknowlege on 
read. This is
+ * why debugfs read and write hooks acquire exclusive access to 
register space.
+ *
+ * Also note this is mostly unusable with power management enabled 
systems since
+ * registers content is lost during power off -> on transitions.
+ */
It would be nice perhaps to tighten up the range of addresses that
we are protecting.  Thus allow reading of any addresses that are not
'fragile'.  Only supported limited debug access is hardly a big
issue however ;)

Quite frankly, I wonder if this debugfs stuff should not be thrown
away given that
regmap already provides a way to access registers over debugfs (with
very limited
protection...).
What do you think ?

[...]

Agreed. Bin it.

Regards,
Grégor.

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