On Wed, 3 Nov 2010, Ohad Ben-Cohen wrote: > On Sun, Oct 31, 2010 at 6:06 PM, Linus Walleij > <[email protected]> wrote: > > This patch modifies the MMC core code to optionally call the > > set_ios() operation on the driver with the clock frequency set > > to 0 (gate) after a grace period of at least 8 MCLK cycles, then > > restore it (ungate) before any new request. This gives > > the driver the option to shut down the MCI clock to the MMC/SD > > Have you considered migrating this to runtime PM API ? > > Runtime PM core already provides most of the necessary plumbing: > referred work, reference counting, tunable delay, active/suspended > status, etc.. > > It will also allow you to avoid overloading the set_ios() operation: > once suspended, host controllers will receive an idle notification > from runtime PM core. also CONFIG_MMC_CLKGATE will probably not be > needed anymore (no API changes so everything should just work as > before. only difference is that now hosts can start supporting these > runtime PM notifications).
While runtime PM might be appropriate, I think that passing a clock rate of 0 to set_ios() is a clear and fully defined state worth supporting. Nothing prevents the later from being used by the former then. Nicolas -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
