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 ? >From my side: Acked-by: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx> -- Thanks, Sylwester -- 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
 |