From mboxrd@z Thu Jan 1 00:00:00 1970 From: khilman@kernel.org (Kevin Hilman) Date: Mon, 15 Dec 2014 14:26:18 -0800 Subject: [PATCH] clk: samsung: Fix Exynos 5420 pinctrl setup and clock disable failure due to domain being gated In-Reply-To: <7hlhmfo1b0.fsf@deeprootsystems.com> (Kevin Hilman's message of "Wed, 10 Dec 2014 09:35:31 -0800") References: <1417788934-23447-1-git-send-email-k.kozlowski@samsung.com> <1418129982.19339.6.camel@AMDC1943> <5486F69B.6020005@samsung.com> <7hlhmfo1b0.fsf@deeprootsystems.com> Message-ID: <7h8ui8h7n9.fsf@deeprootsystems.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Kevin Hilman writes: > Sylwester Nawrocki writes: > >> 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 >>>> > --- >>>> > 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 ? > > I confirm it fixes the boot hang in linux-next (next-20141210) on my > exynos5800-peach-pi and exynos5420-arndale-octa. Tested both > exynos_defconfig and multi_v7_defconfig. > > Tested-by: Kevin Hilman What's the status of this patch? linux-next is still broken for several Exynos5 platforms without this fix. Kevin