Hi Roger, On Tue, Jul 6, 2010 at 11:53 AM, Roger Quadros <roger.quadros@xxxxxxxxx> wrote: > Could you please explain why you need to do this? To minimize power consumption when the wlan device is not in use, we would like to keep the device powered off as long as the interface is down, and only power it on when the user brings up the interface. Whenever the chip is powered on, it must be initialized and reconfigured by mmc_attach_sdio, and the wl1271 driver have to wait for that phase to successfully complete (essentially waiting for the sdio_driver's probe function to be called). To make sure this SDIO init step occurs correctly every time we toggle the device's power back on, and to prevent potential races, we also have to make sure that the sdio function is removed every time we power off the chip (the driver waits for the sdio_driver's remove function to be called). That's why we let the mmc layer think that the card is removed: physically it is still there, but for all practical purposes it is really removed, because once you power off the chip, you must reinitialize it again next time you power it on, as if the card was really removed and re-inserted. Thanks, Ohad. > > br, > -roger > -- 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
