On 07/14, Timur Tabi wrote:

On 07/14/2017 04:46 PM, Stephen Boyd wrote:

quoted

Right, the gpiolib core would need to be updated to request the
gpio in gpiochip_add_data() around the loop where it goes and
configures things. And it could ignore ones that it can't request
there.

__gpiod_request already calls chip->request(), so this would need to
be a temporary request.  It seems a bit hackish, but I'll try it.

Yeah, request, configure, free, in a loop. Unless someone is
aware why we don't do that here.

BTW, I noticed that __gpiod_free() does this:

	if (chip->free) {
		spin_unlock_irqrestore(&gpio_lock, flags);
--->		might_sleep_if(chip->can_sleep);
		chip->free(chip, gpio_chip_hwgpio(desc));
		spin_lock_irqsave(&gpio_lock, flags);


Should __gpiod_request() also call might_sleep_if()?

	if (chip->request) {
		/* chip->request may sleep */
		spin_unlock_irqrestore(&gpio_lock, flags);
---> missing call to might_sleep_if() here?
		status = chip->request(chip, gpio_chip_hwgpio(desc));
		spin_lock_irqsave(&gpio_lock, flags);

Probably. Except we would have caught it earlier when it was
requested?

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