Dear Marek, On 2016년 12월 27일 17:14, Marek Szyprowski wrote: > Dear Chanwoo, > > > On 2016-12-23 18:00, Chanwoo Choi wrote: >> Dear Marek, >> >> I have a question. I agree some clocks should be always on with CLK_IS_CRITICAL. >> CLK_ACLK333 is only used on exynos5420.dtsi. So, I understand to add >> CLK_IS_CRITICAL flag to CLK_ACLK333. >> >> Except for CLK_ACLK333, the remaining clocks with CLK_IS_CRITICAL were >> not used on mainline kernel (arch/arm/boot/dts/*). It means that the >> remaining clocks might be ON before applying this patch. So, >> CLK_IGNORE_UNUSED might be enough to maintain their ON state. >> >> If we don't add the CLK_IGNORE_UNUSED flag to clocks except for >> CLK_ACLK333, are there any problem? >> But, if bootloader don't turn on these clocks, this patch is necessary. > > Please note that CLK_IGNORE_UNUSED doesn't protect clock from turning off as > a result of turn off operation on one of the child-clocks. This patch fixes Right. It was my mistake that I thought the 'aclk_*' clocks are leaf clock. > the boot hang caused by changes in SYSMMU driver, which resulted in turning > off some clocks for G2D domain. Similar issues might happen for other domains > depending on the probe order. Till now it worked only by a luck, because > there was child clock enabled early enough, which protected one of those > clocks from turning off. This patch makes sense. Reviewed-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx> Regards, Chanwoo Choi [snip] -- 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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