> -----Original Message----- > From: linux-mmc-ow...@vger.kernel.org [mailto:linux-mmc- > ow...@vger.kernel.org] On Behalf Of Kevin Liu > Sent: Friday, March 22, 2013 2:55 PM > To: Huang Changming-R66093 > Cc: linux-mmc@vger.kernel.org; Chris Ball; Ulf Hansson > Subject: Re: [PATCH 1/3i v6] MMC/SD: Add callback function to detect card > > 2013/3/22 Huang Changming-R66093 <r66...@freescale.com>: > >> Jerry, > >> > >> Function _mmc_detect_card_removed should only be called when card > >> insert/removal or i/o error occur unless POLLING is used(called once > >> per second). So it should _not_ impact performance much. > > [jerry] > > No, your understanding is wrong. > > Function "_mmc_detect_card_removed " is called to check if our card has > been removed when driver run the function "mmc_rescan" every time. > > > > But when will mmc_rescan be called? > Besides boot up, only when card status change it will be called. > So usually it should _not_ be called frequently. [jerry] For poll mode, how to know card status changed? The answer is "mmc_rescan". maybe you could read the last two lines of this function ago.
> >> POLLING is poor for performance, why not change to slot-gpio if host > >> is broken for card detect. > > [jerry] > > Some our boards can't support interrupt mode to detect card > insert/removable, so we unify the poll mode. > > > > Not support gpio interrupt? > I think you only don't support sdh host interrupt. -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
