Hi, +JJ, Jaehoon Chung I had CCd them in my original mail but they seem to have been dropped in the U-boot list. On Thursday 02 August 2018 03:14 PM, Faiz Abbas wrote: > Hi Everyone, > > After the following patch from JJ, U-boot shifts to a lower speed mode > from HS200 when accessing a boot partition. > > 01298da31d mmc: Change mode when switching to a boot partition > > I have looked through the JESD84-B51 spec for eMMC card and don't see it > say anywhere that boot0 partition cannot be accessed in HS200 modes. > > In practice, I have seen timeouts sometimes when I try to write to the > boot partition in HS200 mode on a dra7xx-evm in U-boot but not > consistently (one would expect if such a thing was forbidden by the spec > then it wouldn't work at all). > > Can anyone point to a documentation that says that boot partition cannot > be accessed in HS200 mode? Has anyone else observed failures before this > patch? > > I was able to access the boot0 partition in kernel in HS200 mode (log > below). Unless there is code to fallback to a lower speed in kernel also > (which doesn't seem to be the case from a simple searching of the code), > this should prove that boot partitions can be accessed in HS200 speed mode. > > Here is the log: > https://pastebin.ubuntu.com/p/W3SB4N3rfn/ > > Thanks, > Faiz > _______________________________________________ > U-Boot mailing list > U-Boot@xxxxxxxxxxxxx > https://lists.denx.de/listinfo/u-boot > -- 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
