Re: [PATCH] at86rf230: Allow slow GPIO pins for "rstn"

From: Stefan Schmidt
Date: Wed Dec 21 2016 - 16:01:36 EST


Hello.

On 21/12/16 19:30, Chris Healy wrote:


On Dec 21, 2016 5:11 AM, "Stefan Schmidt" <stefan@xxxxxxxxxxxxxxx
<mailto:stefan@xxxxxxxxxxxxxxx>> wrote:

Hello.


On 19/12/16 00:25, Andrey Smirnov wrote:

Driver code never touches "rstn" signal in atomic context, so
there's
no need to implicitly put such restriction on it by using
gpio_set_value
to manipulate it. Replace gpio_set_value to
gpio_set_value_cansleep to
fix that.


We need to make sure we are not assuming it can be called in such a
context in the future now. But that is something we can worry about
if it comes up.


As a an example of where such restriction might be inconvenient,
consider a hardware design where "rstn" is connected to a pin of
I2C/SPI
GPIO expander chip.


Is this a real life issue you run into?


I have a platform with this configuration. The DTS for the platform is
in the process of being mainlined right now.

Thanks for letting us know. What platform is that? I'm always interested in hearing about devices that use the Linux ieee802154 subsystem. :)

regards
Stefan Schmidt