Hi Janusz, On 2018-09-21 12:51, Janusz Krzysztofik wrote: > 2018-09-21 10:18 GMT+02:00, Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>: >> On 2018-09-20 18:21, Janusz Krzysztofik wrote: >>> 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: >>>>> 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 >>> >>> >From a919c504850f6cb40e8e81267a3a37537f7c4fd4 Mon Sep 17 00:00:00 2001 >>> From: Janusz Krzysztofik <jmkrzyszt@xxxxxxxxx> >>> Date: Thu, 20 Sep 2018 17:37:21 +0200 >>> Subject: [PATCH] gpiolib: Fix bitmap index not updated >>> While skipping fast path bits, bitmap index is not updated with next >>> found zero bit position. Fix it. >>> >>> Signed-off-by: Janusz Krzysztofik <jmkrzyszt@xxxxxxxxx> >> This one also doesn't help. A quick compare of logs with this version and >> a working system shows, that with your patch (and fix) there are no calls >> to >> gpx0-2 pin (which are a part of mmc pwrseq), what causes mmc failure. If >> you need any more information (what kind of logs will help?), let me know. > There is a debug message on array_info content available at the end of > gpiod_get_array(), could you please activate it and post the message so > we can understand better what is going on? With debug enabled on next-20180919: [ 2.499153] pwrseq_simple mmc3_pwrseq: GPIO array info: chip=gpx0, size=2, get_mask=2, set_mask=2, invert_mask=2 On next-20180920 I get no this message and booting hangs. Same with next-20180920 + your second fix from this thread. I will try to debug this more on Monday. > On the other hand, I've had a look your device-tree configuration and > it looks like that specific setup won't benefit from the fast bitmap path. > You have pin 2 at position 0 and pin 1 at position 1 of the array. > Hence, the fast bitmap path covers only pin 1, and pin 2 is processed > by the old path with apparently buggy code for skipping over fast pins. > > As a temporary workaround, you could try to revert the order of pins in > your dts file (pin 1 at position 0, pin 2 at 1) and the mmc pwrseq code > should work for you again by taking the original old path, not skipping > over fast pins. Results of such check may also help us to better > understand and resolve the issue. Changing the order of mmc pwrseq gpio pins fixes boot hang. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
