2011/10/24 Ulf Hansson <ulf.hansson@xxxxxxxxxxxxxx>: > Could we assume that all boards which utilizes the ARM PL180 are using the > MMCIPWR register to control power the card? Or should we add a new amba mmci > platform member so this is configurable for each board? I think we should take entire variants, like currently U300 and Ux500. In those designs the MMCIPWR signal is left dangling on the chip, so no-one electronics designer can use that signal for anything even if s/he would have wanted to. > An option could also be if we might want to simplify code to just skip the > entire runtime_suspend|idle|resume function (ie stubb it or something) for > these kind of boards? I think the clk_disable()/clk_enable() pair in runtime suspend/resume is still valuable for all other variants too. That has nothing to do with MMCIPWR. > By the way, there is also another option. In the runtime_suspend function > for ARM PL180 block we can use mmc_power_save_host (and then also > disable vcore etc) and vice verse in runtime_resume with > mmc_power_restore_host. This is what the OMAP driver does right? > Of course, these kind of operations takes quite some time to execute and > therefore we use a much bigger timeout than 50 ms (for example 10 s > instead) for ARM PL180. Can we do both? 1) Break out mmci_state_save_restore() from the runtime PM hooks. 2) I.e. have a short time-out that will runtime-suspend the external regulator variants quickly with finer granularity. 3) Have a long time-out that will runtime-suspend the MMCIPWR variants using mmc_power_save_host() with a longer delay? Since mmc_power_save_host() calls .set_ios() to really shut down the power to the card we should be on the safe side. Looks like a nice silver bullet to me :-) I volunteer to test the long time-out code path on the Integrator PB1176 to verify this works. 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
