Messages in this thread |  | | Date | Tue, 5 Feb 2013 18:00:56 +0100 | Subject | Re: [PATCH 1/9] gpiolib: link all gpio_chips using a list | From | Linus Walleij <> |
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On Sat, Feb 2, 2013 at 5:29 PM, Alexandre Courbot <acourbot@nvidia.com> wrote:
> Add a list member to gpio_chip that allows all chips to be parsed > quickly. The current method requires parsing the entire GPIO integer > space, which is painfully slow. Using a list makes many chip operations > that involve lookup or parsing faster, and also simplifies the code. It > is also necessary to eventually get rid of the global gpio_desc[] array. > > The list of gpio_chips is always ordered by base GPIO number to ensure > chips traversal is done in the right order. > > Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
OK!
> + * Return -EBUSY if the new chip overlaps with some other chip's integer > + * space. (...) > + /* are we stepping on the chip right before? */ > + if (pos != &gpio_chips && pos->prev != &gpio_chips) { > + _chip = list_entry(pos->prev, struct gpio_chip, list); > + if (_chip->base + _chip->ngpio > chip->base) { > + dev_err(chip->dev, > + "GPIO integer space overlap, cannot add chip\n"); > + err = -EBUSY; > + } > + }
This robustness change on its own is a merit for merging the patch. And keeping a list of gpiochips available is great for stuff like debugfs.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Yours, Linus Walleij
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