fd68bd0f5d
Due to the way attribute groups visibility work, the function cros_ec_lightbar_attrs_are_visible is called multiple times, once per attribute, and each of these calls makes an EC transaction. For what is worth the EC log reports multiple errors on boot when the lightbar is not available. Instead, check if the EC has a lightbar in the probe function and only instantiate the device. Ideally we should have instantiate the driver only if the EC_FEATURE_LIGHTBAR is defined, but that's not possible because that flag is not in the very first Pixel Chromebook (Link), only on Samus. So, the driver is instantiated by his parent always. This patch changes a bit the actual behaviour. Before the patch if an EC doesn't have a lightbar an empty lightbar folder is created in /sys/class/chromeos/<ec-device-name>, after the patch the empty folder is not created, so, the folder is only created if the lightbar exists. Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Reviewed-by: Guenter Roeck <groeck@chromium.org> Signed-off-by: Lee Jones <lee.jones@linaro.org>
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.