Hi Guennadi, On Tuesday 12 June 2012 15:31:49 Guennadi Liakhovetski wrote: > On Tue, 12 Jun 2012, Laurent Pinchart wrote: > > The tmio_mmc_set_ios() function configures the MMC power, clock and bus > > width. When the MMC controller gets powered off, runtime PM switches the > > MSTP clock off. Writing to to CTL_SD_MEM_CARD_OPT register afterwards > > fails and prints an error message to the kernel log. > > > > As configuring the bus width is pointless when the interface gets > > powered down, skip the operation when power is off. > > The patch looks good - thanks! But maybe we can make the commit message a > bit more precise. I think, ios->power_mode refers to powering the card > down and up, not the controller. We use this information to also try to > put the controller in a power-saving mode. Depending on the kernel and > board configuration this can be a NOP, it can switch the MSTP clock off, > as you correctly notice, or it can power the whole PM domain, to which the > controller belongs, down. So, maybe something like this would be better: > > The tmio_mmc_set_ios() function configures the MMC power, clock and bus > width. When the mmc core requests the driver to power off the card, we > inform runtime PM, that the controller can be suspended. This can lead to > the MSTP clock being turned off. Writing to to CTL_SD_MEM_CARD_OPT > register afterwards fails and prints an error message to the kernel log. > > As conf... (continue as above) > > Feel free to further improve the above :) Thank you for the feedback. I'll send a v2 that incorporates a second related fix. -- Regards, Laurent Pinchart -- 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
