Re: [PATCH v7 4/4] gpiolib: Implement fast processing path in get/set array

[Janusz Krzysztofik]

On Thursday, September 20, 2018 12:11:48 PM CEST Marek Szyprowski wrote:
> Hi All,
> 
> On 2018-09-02 14:01, Janusz Krzysztofik wrote:
> > Certain GPIO descriptor arrays returned by gpio_get_array() may contain
> > information on direct mapping of array members to pins of a single GPIO
> > chip in hardware order.  In such cases, bitmaps of values can be passed
> > directly from/to the chip's .get/set_multiple() callbacks without
> > wasting time on iterations.
> >
> > Add respective code to gpiod_get/set_array_bitmap_complex() functions.
> > Pins not applicable for fast path are processed as before, skipping
> > over the 'fast' ones.
> >
> > Cc: Jonathan Corbet <corbet@xxxxxxx>
> > Signed-off-by: Janusz Krzysztofik <jmkrzyszt@xxxxxxxxx>
> 
> I've just noticed that this patch landed in today's linux-next. Sadly it
> breaks booting of Exynos5250-based Samsung Snow Chromebook (ARM 32bit,
> device-tree source arch/arm/boot/dts/exynos5250-snow.dts).
> 
> Booting hangs after detecting MMC cards. Reverting this patch fixes the
> boot. I will try later to add some debugs and investigate it further what
> really happens when booting hangs.

Hi Marek,

Thanks for reporting. Could you please try the following fix?

Thanks,
Janusz