Re: [PATCH] gpio/langwell: re-read the IRQ status register after each iteration

[Linus Walleij]

On Thu, May 10, 2012 at 12:01 PM, Mika Westerberg
<mika.westerberg@xxxxxxxxxxxxxxx> wrote:

> Spotted by Grant Likely. The IRQ status register should be re-read after
> each iteration. Otherwise the loop misses the interrupt if it gets raised
> immediately after handled.
>
> Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> ---
> This patch applies on top of my previous patch ("gpio: langwell: convert to
> use irq_domain").

Oh yeah that thing I recognize!
Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

If someone has  time I think it would be a good idea to
conjure a cocienelle sematic patch to catch this pattern, because
I suspect it might exist in more IRQ handlers.

-               pending = readl(gedr);
-               while (pending) {
+               while ((pending = readl(gedr))) {
                       gpio = __ffs(pending);
                       mask = BIT(gpio);
-                       pending &= ~mask;

Yours,
Linus Walleij
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