On Mon, Oct 24, 2011 at 11:36 AM, Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> wrote: > On Sun, Oct 23, 2011 at 02:31:39AM +0200, Sebastian Rasmussen wrote: >> I guess the patch would appeal more to Russell if mmci_runtime_suspend() >> only cleared MCIMask0/SDI_MASK0 and MCIClock/SDI_CLKCR and left >> MCIPower/SDI_PWR unchanged. It may be the case that the signal direction >> bits need to be cleared for the ST-Ericsson PL180, but I haven't yet verified >> this on my Snowball dev board yet. > > There's also the issue that the specs call for the clock to run after > a command has completed for a certain number of cycles, and that the > clock must continue to run until the card reports not-busy after a > programming or erase cycle has completed - that can be long after the > previous command has 'completed'. It's 8 cycles on MCLK required. I think that is taken care of by this: pm_runtime_set_autosuspend_delay(mmc->parent, 50); 50 ms is >> 8 MCLK in any practical case, but if we want to be really, really sure we can always: #define DEFAULT_DELAY 50 int delay; delay = DIV_ROUND_UP((1000 * 8), host->mclk); /* 8 MCLK in ms */ delay = max(DEFAULT_DELAY, min_delay); pm_runtime_set_autosuspend_delay(mmc->parent, delay); So we have encoded all assumptions. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
