On 8 November 2014 at 01:14, NeilBrown <neilb@xxxxxxx> wrote: > If the regulator supplying an SDIO device is shared > with another device, the turning the regulator 'on' and 'off' > will not actually cycle power and so will not reset > the device. > > This is particularly a problem for some wi2si wireless modules which > have a BT module on chip and can share power lines. > Without the power-cycle, subsequent reset commands fail. > > So allow a 'reset' gpio to be specified. If provided, the > line is asserted during power-up. There have been several attempts to fix similar issues as this patch does. The latest one I posted a few month ago, which wasn't accepted. http://comments.gmane.org/gmane.linux.power-management.general/46635 There has also been some off-list discussions on especially how we should describe this in DT and there were actually some consensus made around that. Still I haven't seen any patches on the mailing lists. So to summarize, I am really concerned that we keep having these power sequence issues for SDIO devices and right now the discussion has been on hold. I am considering to hack on it myself, since I am tired of waiting. :-) Regarding this patch, I don't intent to apply it. Kind regards Uffe -- 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
