On 15 January 2015 at 10:20, Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx> wrote: > On czw, 2015-01-15 at 09:20 +0100, Ulf Hansson wrote: >> + Mike, Stephen (Clock maintainers) >> >> On 12 January 2015 at 10:23, Krzysztof Kozlowski >> <k.kozlowski@xxxxxxxxxxx> wrote: >> > Hi, >> > >> > >> > I would like to hear some comments about idea of scaling MMC clock >> > frequency. The basic idea is to lower the clock when device is >> > completely idle or not busy enough. >> >> We already have host drivers that implements runtime PM support. >> Typically that would mean the clock will be gated once the device >> becomes runtime PM suspended. >> >> Why should we decrease the frequency of an already gated clock? > > In case of idle state you're right that clkgate would be better. But > what about finding a compromise between high performance (high > frequency) and energy saving for different loads on MMC? I guess a compromise could be beneficial for some SOC and use cases. At least I remember, ST-Ericsson's UX500 SOC had such an out of tree hack to track MMC load. > > The frequency scaling could help in that case. Anyway I should prepare > some more benchmarks for such conditions. Seems reasonable and please do! Kind regards Uffe -- 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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