[U-Boot] [PATCH 00/22] mmc: Add support for HS200 and UHS modes

Fri Jun 2 16:46:04 UTC 2017

On 25/05/2017 09:41, Jaehoon Chung wrote:
> Hi,
>
> On 05/24/2017 12:24 AM, Jean-Jacques Hiblot wrote:
>> Hi,
>>
>>
>> On 18/05/2017 06:27, Jaehoon Chung wrote:
>>> Hi,
>>>
>>> On 05/13/2017 03:16 AM, 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). 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 4 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:
>>>> - enable/disable Vdd
>>>> - check if the card is busy (used during UHS voltage switching)
>>>> - 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.
>>>>
>>>> And finally the last commits add the support for HS200 and UHS.
>>>> I haven't been able to test the UHS SDR104 mode by lack of compatible sdcard.
>>> After testing my targets, some boards don't work fine..So i'm checking this problem..
>> Jaehoon,
>>
>> what kind of issues are you running into and on what platforms ?
>> So far, besides the items brought-up by the reviews, there are 2 issues that are in the pipe for the next version:
>>   * signal voltage selection is not done for the MMCs only for SDs.
>>   * I noticed a timing constraint in voltage selection for SDs that can be a problem when trying a UHS mode with some SDs (seen only with Sandisk Ultra  64Gb micro SD class I) :  the voltage must be switched quickly after the cmd SWITCH_UHS18V has been sent, making debug messages in that context a problem. With this SD I've been able to check that SDR104 is working.
> How about making the "testing-hs200-uhs" branch for this? It needs to test more..
Jaehoon,

Have you been able to track down the issue you had with your boards ? 
Next week I can borrow some boards if it can help (at91 and imx6 based), 
have they been part of your tests ?

Also I set up a repository with the code for testing:
git at github.com:jjhiblot/u-boot.git testing-hs200-uhs_v2

If you have a omap5 based board (dra7 or am57), you can test with this 
branch that also includes the host support for high speed modes:
git at github.com:jjhiblot/u-boot.git high_speed_hsmmc

Regards,

Jean-jacques

****
> I guess my target doesn't do the voltage change..i'm doing for ufs driver on u-boot in my local..
> So i didn't see fully..today i have a free time..So i'm doing full review other thing..and about pending patches.
>
> Thanks for waiting me.. :)
>
> Best Regards,
> Jaehoon Chung
>
>> Jean-Jacques
>>>> With this in place and the required changes in the HSMMC (including DAM), we observe significant
>>>> improvements in the performances on a DRA7 evm:
>>>> eMMC HS200: 130 MB/s
>>>> eMMC DDR52: 80 MB/s
>>>> sd   SDR50: 80 MB/s
>>>>
>>>> cheers,
>>>>
>>>> Jean-Jacques
>>>>
>>>>
>>>> Jean-Jacques Hiblot (18):
>>>>     mmc: split mmc_startup()
>>>>     mmc: move the MMC startup for version above v4.0 in a separate
>>>>       function
>>>>     mmc: make ext_csd part of struct mmc
>>>>     mmc: add a function to read and test the ext csd (mmc >= 4)
>>>>     mmc: introduces mmc modes.
>>>>     mmc: Add a fonction to dump the mmc capabilities
>>>>     mmc: use mmc modes to select the correct bus speed
>>>>     cmd: mmc: display the mode name and current bus speed in the mmc info
>>>>     mmc: refactor SD startup to make it easier to support new modes
>>>>     mmc: refactor MMC startup to make it easier to support new modes
>>>>     mmc: make mmc_set_ios() return status
>>>>     mmc: add power cyle support in mmc core
>>>>     mmc: add a new mmc parameter to disable mmc clock
>>>>     mmc: Add a execute_tuning() callback to the mmc operations.
>>>>     mmc: add HS200 support in MMC core
>>>>     mmc: Add a new callback function to check if the card is busy
>>>>     mmc: Add support for UHS modes
>>>>     mmc: Change mode when switching to a boot partition
>>>>
>>>> Kishon Vijay Abraham I (3):
>>>>     mmc: Enable signal voltage to be selected from mmc core
>>>>     mmc: Add a new callback function to enable/disable vdd
>>>>     mmc: disable the mmc clock during power off
>>>>
>>>> Vignesh R (1):
>>>>     mmc: Retry some MMC cmds on failure
>>>>
>>>>    cmd/mmc.c                |    3 +-
>>>>    drivers/mmc/fsl_esdhc.c  |    2 +-
>>>>    drivers/mmc/mmc-uclass.c |   42 ++
>>>>    drivers/mmc/mmc.c        | 1220 +++++++++++++++++++++++++++++++++-------------
>>>>    include/mmc.h            |  138 +++++-
>>>>    5 files changed, 1058 insertions(+), 347 deletions(-)
>>>>
>>
>>
>>
>