Re: [PATCH] gpiolib: Show correct direction from the beginning

From: Timur Tabi
Date: Thu Sep 20 2018 - 08:25:22 EST


On 9/19/18 10:27 AM, Ricardo Ribalda Delgado wrote:
"The get_direction callback normally triggers
a read/write to hardware, but we shouldn't be touching the hardware
for an individual GPIO until after it's been properly claimed." is
an statement specific for your platform

That is definitely not true.

and should be fixed in your
driver.

There is no bug in my driver. The driver reports only a subset of the GPIOs, because that's all that are available. Attempting to access an invalid GPIO generates an XPU violation. The original code was attempting to access GPIOs that the driver said don't exist.

The code that we have today is the result of months of discussion, negotiation, and trial-and-error.