Hello Marek, On 01/20/2017 05:08 AM, Marek Szyprowski wrote: > Hi Javier, > [snip] >> Ok, I misunderstood the relationship between runtime PM and the power domains >> then. I thought the power domains were only powered on when the runtime PM >> framework resumed an associated device (i.e: pm_runtime_get_sync() is called). > > Power domains are implemented transparently for the drivers. Even when driver > doesn't support runtime pm, but its device is in the power domain, the core will > ensure that the domain will be turned on all the time the driver is bound to the > device. > I got it now, thank a lot for your explanation. >> But even if this isn't the case, shouldn't the reset in probe only be needed >> if CONFIG_PM isn't enabled? (IOW, $SUBJECT but with another commit message). > > This looks like an over-engineering. I don't like polluting driver code with > conditional statements like IS_ENABLED(CONFIG_*). It should not hurt to reset > the device in driver probe, especially just in case the device was left in > some partially configured/working state by bootloader or previous kernel run > (if started from kexec). Adding this conditional code to avoid some issues > with power domain or clocks configuration also suggests that one should > instead solve the problem elsewhere. Driver should be able to access device > registers in its probe() in any case without the additional hacks. > Fair enough, I already posted the patch but I'll ask it to be dropped. [snip] >> >> This seems to be caused by some needed clocks to access the power domains >> to be gated, since I don't get these erros when passing clk_ignore_unused >> as parameter in the kernel command line. > > I think that those issues were fixes by the following patch: > https://patchwork.kernel.org/patch/9484607/ > It still didn't reach mainline, but I hope it will go as a fix to v4.10. > That won't be enough since the CLK_ACLK432_SCALER needs to be ungated for Exynos5422/5800 as mentioned on another mail in this thread. > Please test if this solves your issue. Please not that adding more clocks > to the power domain drivers will solve only the problem with turning domain > on/off, but the are more cases where those clocks should be turned on (like > IOMMU integration), so marking them as critical solves that problem too. > Ok, I understand your point. > Best regards Best regards, -- Javier Martinez Canillas Open Source Group Samsung Research America -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
