Skip to content
Snippets Groups Projects
user avatar
Thomas Petazzoni authored
The Zynq GPIO driver currently implements runtime PM by:

 - Enabling runtime PM support in ->probe() and letting the runtime PM
   reference counter drop to zero at the end of ->probe().

 - Increasing the runtime PM reference counter in ->request() and
   decreasing it in ->free().

However, the latter is not sufficient: when a GPIO is used as an
interrupt, ->request() and ->free() are not called. Due to this, the
runtime PM counter remains to zero when the only GPIOs in use are used
as interrupts, causing them to simply not work.

To address this problem, this commit implement the
->irq_request_resources() and ->irq_release_resources() hooks,
ensuring that the runtime PM counter is properly
incremented/decremented. Since we override the default hooks, we keep
the existing behavior by making sure they call gpiochip_reqres_irq() /
gpiochip_relres_irq() respectively.

Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@bootlin.com>
Reviewed-by: default avatarShubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
c2df3de0
History
Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.