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

[Janusz Krzysztofik]

On Thursday, September 20, 2018 5:48:22 PM CEST Janusz Krzysztofik wrote:
> 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?

Hi again,

I realized the patch was not correct, j, not i, should be updated in second 
hunk. Please try the following one.

Thanks,
Janusz