Hi On Fri, Apr 3, 2015 at 9:50 PM, Marco Cavallini <cavallini.k...@gmail.com> wrote: > 2015-03-30 17:32 GMT+02:00 Marco Cavallini <cavallini.k...@gmail.com>: >> Hello, >> I am probably working on a 'buggy hardware' based on i.MX6 that isn't >> able to manage a SDcard speed properly. >> I mean, u-boot starts, but as soon as I try to perform a fatload if >> the uImage the command won't work properly. >> I had the possibility to test the SoM on another carrier with a >> different layout and a different microSD connector and it works at >> every boot. >> The quick and dirty hack I found is to modify sd_switch() in >> drivers/mmc/mmc.c in this way >> >> /* >> * Reduce SD/MMC speed >> * u-boot> mmc info >> * before : Tran Speed: 50000000 >> * after : Tran Speed: 25000000 >> */ >> printf("*** Skip support SD_HIGHSPEED in sd_change_freq\n") ; >> return 0; >> >> just before >> >> /* If high-speed isn't supported, we return */ >> if (!(__be32_to_cpu(switch_status[3]) & SD_HIGHSPEED_SUPPORTED)) >> return 0; >> >> the problem is that on 80% of the carrier boards the problem is still >> present. >> My questions are: >> 1. is this hack the best solution in this case or can you suggest me >> another better way to proceed? >> 2. would be possible to reduce the speed more than this and how? >>
Increase the divisor of the clock MXC_CCM_CSCDR1_USDHC[X]_PODF_MASK MXC_CCM_CSCDR1_USDHC[X]_PODF_OFFSET I'm not sure because I have not a board and no time before Easter to open documentation ;) Michael >> thank you in advance >> -- >> Marco > > > Hello, > sorry for bothering you. > Any advice from the u-boot experts would give me a great help. > Thank you > _______________________________________________ > U-Boot mailing list > U-Boot@lists.denx.de > http://lists.denx.de/mailman/listinfo/u-boot _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot