On 04/24/2014 03:36 PM, Tomasz Figa wrote: > On 24.04.2014 11:07, Tushar Behera wrote: >> On 04/23/2014 03:43 PM, Kukjin Kim wrote: >>> Tushar Behera wrote: >>>> >>>> On 22 April 2014 13:08, Alim Akhtar <alim.akhtar@xxxxxxxxx> wrote: >>>>> Hi Tushar >>>>> >>>>> On Tue, Apr 22, 2014 at 11:09 AM, Tushar Behera >>>>> <tushar.behera@xxxxxxxxxx> wrote: >>>>>> MAU powerdomain provides clocks for Audio sub-system block. This >>>>>> block >>>>>> comprises of the I2S audio controller, audio DMA blocks and Audio >>>>>> sub-system clock registers. >>>>>> >>>>>> Right now, there is no way to hook up power-domains with clock >>>> providers. >>>>>> During late boot when this power-domain gets disabled, we get >>>>>> following >>>>>> external abort. >>> >>> + Jonghwan Choi >>> >>> Well, this is not a perfect solution to support MAU power domain, >>> it's true it is a problem right now though. >>> >>> In other words, this is just temporal fix for the problem. >>> >>> How about accessing clock stuff for audio sub-system with handling >>> MAU power domain via generic IO power domain? >>> >> >> + Tomasz Figa >> >> Existing power domain driver exynos4_pm_init_power_domain is registered >> with an arch_initcall whereas the clk-exynos-audss driver is registered >> with core_initcall. Hence even if add mau_pd node to clk-exynos-audss >> node, the binding with power-domain doesn't happen. > > I'd say core_initcall is way too early for clk-exynos-audss driver. It > should be at most subsys_initcall. As far as I can see, all users of > clocks provided by this driver (i.e. i2s) are probed at device_initcall > level anyway. > It is also used by ADMA node, which gets probed. >> >> Alternately, if Tomasz's patches are applied [1], power-domain binding >> is successful. But because of the init order, clk-exynos-audss defers >> probe resulting in a kernel crash. Forcing clk-exynos-audss to register >> through arch_initcall() fixes this issue, but I am not sure if that is >> okay. > > If the driver crashes on deferred probe, then it's a bug and it should > be fixed. > By the time clk-exynos-audss is getting called, mau_pd is already disabled by power-domain driver. That is not getting enabled during clk-exynos-audss probe. Am I missing something? > Best regards, > Tomasz -- Tushar Behera -- 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
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