From: s.nawrocki@samsung•com (Sylwester Nawrocki)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] clk: samsung: Fix Exynos 5420 pinctrl setup and clock disable failure due to domain being gated
Date: Tue, 09 Dec 2014 14:18:19 +0100 [thread overview]
Message-ID: <5486F69B.6020005@samsung.com> (raw)
In-Reply-To: <1418129982.19339.6.camel@AMDC1943>
On 09/12/14 13:59, Krzysztof Kozlowski wrote:
> On pi?, 2014-12-05 at 15:15 +0100, Krzysztof Kozlowski wrote:
>> > Audio subsystem clocks are located in separate block. On Exynos 5420 if
>> > clock for this block (from main clock domain) 'mau_epll' is gated then
>> > any read or write to audss registers will block.
>> >
>> > This kind of boot hang was observed on Arndale Octa and Peach Pi/Pit
>> > after introducing runtime PM to pl330 DMA driver. After that commit the
>> > 'mau_epll' was gated, because the "amba" clock was disabled and there
>> > were no more users of mau_epll.
>> >
>> > The system hang on one of steps:
>> > 1. Disabling unused clocks from audss block.
>> > 2. During audss GPIO setup (just before probing i2s0 because
>> > samsung_pinmux_setup() tried to access memory from audss block which was
>> > gated.
>> >
>> > Add a workaround for this by enabling the 'mau_epll' clock in probe.
>> >
>> > Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung•com>
>> > ---
>> > drivers/clk/samsung/clk-exynos-audss.c | 29 ++++++++++++++++++++++++++++-
>> > 1 file changed, 28 insertions(+), 1 deletion(-)
>
> Sorry for pinging so quick but merge window is open and it looks like
> booting Exynos542x boards will be broken (because pl330 will no longer
> hold adma clock enabled so whole audss domain will be gated).
>
> This is a non-intrusive workaround for that issue, as wanted by
> Sylwester:
> https://lkml.org/lkml/2014/12/5/223
>
> Any comments on this?
The patch looks OK to me, it would be good though if someone else
has confirmed it fixes the bug. I don't have any clock patches queued
at the moment. Perhaps you could apply it directly, Mike ?
>From my side:
Acked-by: Sylwester Nawrocki <s.nawrocki@samsung•com>
--
Thanks,
Sylwester
next prev parent reply other threads:[~2014-12-09 13:18 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-05 14:15 [PATCH] clk: samsung: Fix Exynos 5420 pinctrl setup and clock disable failure due to domain being gated Krzysztof Kozlowski
2014-12-09 12:59 ` Krzysztof Kozlowski
2014-12-09 13:18 ` Sylwester Nawrocki [this message]
2014-12-09 14:05 ` Javier Martinez Canillas
2014-12-10 17:35 ` Kevin Hilman
2014-12-15 22:26 ` Kevin Hilman
2014-12-16 8:20 ` Krzysztof Kozlowski
2014-12-17 15:23 ` Mike Turquette
2014-12-18 6:58 ` Mike Turquette
2014-12-18 22:10 ` Kevin Hilman
2014-12-18 22:32 ` Mike Turquette
2014-12-24 16:36 ` Paolo Pisati
2015-01-02 9:49 ` Javier Martinez Canillas
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