On 30 May 2011 07:52, Ohad Ben-Cohen <ohad@xxxxxxxxxx> wrote: > On Sun, May 29, 2011 at 7:21 PM, Daniel Drake <dsd@xxxxxxxxxx> wrote: >> It's certainly possible that there's something weird about the >> hardware in question, but we *are* able to successfully power down and >> up the card with a hacky rfkill driver that calls mmc_stop_host / >> mmc_start_host. > > Are we talking about the XO-1.5 and the sd8686 ? Yes. > Last we talked, we found out runtime PM didn't work because the sd8686 > required an additional manipulation of an external reset gpio line, > and that the only reason OLPC could power it down/up was this patch: > > http://dev.laptop.org/git/olpc-2.6/commit/?h=olpc-2.6.35&id=e9bee721fb0cc303286d1fe5df4930ce79b0b1e0 My further investigation here suggests that this change is not necessary. It was added in response to a separate (hard-to-reproduce) issue and it was never known if it would actually fix that issue, it was more of a guess. We don't have any convincing evidence that it helps, so it will be dropped in future. Anyway, just to be sure, I tried combining this hack with runtime PM, and also as a regulator, and it didn't help anything. runtime PM still fails to power up the card. Sorry for leading you down the wrong path there. > does mmc_stop_host+mmc_start_host > work for you without manipulating that reset gpio ? Yes. ... > Otherwise, submit :) Thanks for reviewing, I'll go ahead and clean it up. You didn't comment on the added mmc_select_voltage() call. Is that one also sensible? Thanks, Daniel -- 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
