Hi Lubomir, thanks for your patch! On Wed, Oct 10, 2018 at 4:26 PM Lubomir Rintel <lkundrak@xxxxx> wrote: > Take the GPIO lines are used by the SP. The driver doesn't touch the > lines -- this is done to disallow anything else from fiddling with > them because that would confuse the SP firmware. > > Also, the lines are now nicely visible in /sys/kernel/debug/gpio. > > Signed-off-by: Lubomir Rintel <lkundrak@xxxxx> Sadly I do not think this is the right way to do this these days. In the past I would have agreed. A few months back, Qualcomm engineers working on ACPI support ran into similar issues: there were GPIO lines that could not be touched by the kernel because they were used by firmware (BIOS). The solution we devised can be seen in commit 726cb3ba49692bdae6caff457755e7cdb432efa4 "gpiolib: Support 'gpio-reserved-ranges' property" which adds a "valid mask" to struct gpio_chip. It is further refined in the lates working kernel code to make it easy for users to set up a custom valid_mask. https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio.git/commit/?h=devel&id=f8ec92a9f63b3b11e399409141b7868bb405e6b5 So what you should do is modify the platform set-up for the OLPC to mask off these GPIO lines as invalid since they are used by the firmware and Linux should not touch them. Sadly I don't know which GPIO driver the XO1 is using, but if you tell us I bet me or Andy will be able to help you out in finding the right spot to patch. Yours, Linus Walleij
