Messages in this thread |  | | Date | Tue, 5 Feb 2013 19:01:34 +0100 | Subject | Re: [PATCH 8/9] gpiolib: use gpio_chips list in gpio_to_desc | From | Linus Walleij <> |
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On Sat, Feb 2, 2013 at 5:29 PM, Alexandre Courbot <acourbot@nvidia.com> wrote:
> Parse the list of chips to find the descriptor corresponding to a GPIO > number instead of directly picking the entry of the global gpio_desc[] > array, which is due to be removed. > > This turns the complexity of converting a GPIO number into a descriptor > from O(1) to O(n) where n is the number of GPIO chips in the system. > Since n is ought to be small anyway, there should be no noticeable > performance impact. Moreover, GPIO users who care for speed already have > implemented their own gpio_get_value() and gpio_set_value() with a > fast path for the GPIO numbers that matter and this change does not > affect such use cases. > > The descriptor-based GPIO API, due to be introduced soon, will make this > lookup unnecessary. > > Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
OK it's a nice stepping stone.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Yours, Linus Walleij
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