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

Fri Jun 16 10:00:42 UTC 2017

Hi Jaehoon,

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..
> 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.. :)

I updated the branches for testing in my github repo 
(https://github.com/jjhiblot/u-boot.git )
branch testing-hs200-uhs_v2 touches only the MMC core
branch high_speed_hsmmc_v2 implements the required bit for th HSMMC 
found on TI boards

Most of the comments (if not all of them) have been taken in account and 
the branches have been rebased on top of u-boot master.

Will you be able to do some testing and let me know if there are other 
things to change ? Don't hesitate to let me know what boards it breaks 
(if any), I'll do my best to get my hands on one and help with the 
debugging.

Thanks,

JJ
>
> 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(-)
>>>>
>>
>>
>>
>