On pon, 2014-12-15 at 14:26 -0800, Kevin Hilman wrote: > Kevin Hilman <khilman@xxxxxxxxxx> writes: > > > Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx> writes: > > > >> On 09/12/14 13:59, Krzysztof Kozlowski wrote: > >>> On pią, 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@xxxxxxxxxxx> > >>>> > --- > >>>> > 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 <khilman@xxxxxxxxxx> > > What's the status of this patch? linux-next is still broken for several > Exynos5 platforms without this fix. I believe not only next is broken but also current mainline because runtime PM for pl330 was merged yesterday... The patch received two tested-bys (Kevin's and Javier's) and Sylwester's ack. Mike, could you pick the patch and send it to Linus after rc1? Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
 |