Hi, Andy Could you give some reason why eMMC device will be so slowed down by re-initialization? I think eMMC device is initialized only once, except it invoke 'mmc_init' many times.
The workaround "mmc rescan" works when replace the card. But if one card is removed, then use "mmcfinfo": there is no card present, while the previous card information is displayed, I don't' think it make sense. => mmc rescan MMC: no card present => mmcinfo MMC: no card present Device: FSL_SDHC Manufacturer ID: 2 OEM: 544d Name: SD04G Tran Speed: 50000000 Rd Block Len: 512 SD version 2.0 High Capacity: Yes Capacity: 3.7 GiB Bus Width: 4-bit Best Regards Jerry Huang > -----Original Message----- > From: Andy Fleming [mailto:aflem...@gmail.com] > Sent: Saturday, July 14, 2012 5:33 AM > To: Huang Changming-R66093 > Cc: u-boot@lists.denx.de; Marek Vasut > Subject: Re: [PATCH 1/2 v2] SDHC/MMC: fix the wrong infomation after > change SD card > > On Wed, Jul 11, 2012 at 4:29 AM, Huang Changming-R66093 > <r66...@freescale.com> wrote: > > Hi, Andy, > > There is not any feedback for very long time, > > Could it be applied to the u-boot? > > > I'm afraid I have to reject this patch. We need to find a better > solution to the two problems: > > 1) We want to change cards and still have mmc commands work > 2) We don't want eMMC devices to be slowed down by constantly > re-initializing their cards. > > Normally, I would err on the side of #1, but there's a simple > workaround. If you replace the card, execute "mmc rescan", and the > card will be reinitialized. Please let me know if that workaround > doesn't work. I hope, in the future, we'll have some code which makes > both possible, by being able to detect that a card has been changed, > but for now I think the current system is reasonably satisfactory to > both cases #1 and #2. > > Andy _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot