On 10/02/2017 11:15 AM, Jean-Jacques Hiblot wrote: > > > On 22/09/2017 16:42, Jaehoon Chung wrote: >> Dear JJ, >> >> On 09/21/2017 11:29 PM, Jean-Jacques Hiblot wrote: >>> This series brings support for HS200 and UHS modes to the mmc core. >>> It has been tested with the hsmmc driver on several platforms (DRA7, >>> AM57x, AM437x, beaglebone black, Atmel SAMA5D3 xplained). Some >>> modifications >>> are required in the host driver to take advantage of this (voltage >>> switching, >>> tuning). The changes to the host driver will be posted a another >>> series as this >>> one is already long enough. >>> >>> The series starts with a small refactoring of th sd/mmc startup. The >>> first 5 commits >>> are mostly moving code around with little or no functionnal change. >>> >>> Then the notion of "mode" is introduced. Until now, this information >>> wasn't >>> kept in struct mmc. Only the clock and a flag for ddr was kept. Later >>> the mode >>> information will be used to select the clock frequency, the ddr flag >>> and the >>> tuning procedure. It will be also be check against the host >>> capabilities. >>> >>> Then comes the big refactoring job in: >>> "mmc: refactor MMC startup to make it easier to support new modes" and >>> "mmc: refactor SD startup to make it easier to support new modes" >>> Since the number of modes is increasing, it makes sense to try them >>> in a more >>> organized way. those commits use a list of supported modes and >>> iterate through >>> them to find the best working one. It also allows to switch more >>> easilly from >>> one mode to another (switching from HS200 to DDR52 to access boot >>> partitions for example) >>> >>> Then there are a couple of new callback added to: >>> - send the initialization stream (74 clock cycles) >>> - wait while the card is busy (used during UHS voltage switching). >>> checking is >>> done on dat0. >>> - select the IO voltage >>> >>> Then Power cycle is added. Without power cycle, if a UHS card fails >>> to enumerate in >>> UHS mode, it can't fall back to high speed mode and card enumeration >>> will fail. >>> Also in case of a reset (as opposed to a power on), it ensures that >>> the SDCard >>> is in clean state before re-doing the initialization. >>> >>> And finally the last commits add the support for HS200 and UHS. >>> >>> With this in place and the required changes in the HSMMC host driver >>> (including >>> DMA), we observe significant improvements in the performances on a >>> DRA72 evm: >>> eMMC HS200: 124 MB/s >>> eMMC DDR52: 78 MB/s >>> sd SDR104: 71 MB/s >>> sd SDR50: 44 MB/s >> I have one question. >> >> Did you test about accessing Boot partition of eMMC? > >> As i know, boot partition doesn't support the HS200 mode. >> >> When i checked your patches, there is no the function of mode changing >> for accessing boot partition. >> If i missed it, let me know, plz. > Yes I did test the boot partitions. HS200 is not used in this case. > The key function is mmc_boot_part_access_chk(). It checks if the current > mode is supported by the partition. If not, it'll reselect a new mode.
Is anything new happening on the HS200 front ? -- Best regards, Marek Vasut _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
