[U-Boot] mmc1 not working on Samsung snow chromebook

[Guillaume Gardet]

I found a workaround. If I disable MMC_MODE_HS_52MHz, then it is working fine.

I guess there is a better way to implement the following patch ?

**********************************************************************
diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
index 23f642980b..a6a0934eef 100644
--- a/drivers/mmc/dw_mmc.c
+++ b/drivers/mmc/dw_mmc.c
@@ -508,7 +508,8 @@ void dwmci_setup_cfg(struct mmc_config *cfg, struct dwmci_host *host,
                 cfg->host_caps |= MMC_MODE_4BIT;
                 cfg->host_caps &= ~MMC_MODE_8BIT;
         }
-       cfg->host_caps |= MMC_MODE_HS | MMC_MODE_HS_52MHz;
+       /* MMC_MODE_HS_52MHz is broken (at least) on Samsung Snow, so disbale it for now */
+       cfg->host_caps |= MMC_MODE_HS;

         cfg->b_max = CONFIG_SYS_MMC_MAX_BLK_COUNT;
  }
**********************************************************************


Guillaume



Le 15/11/2017 à 11:27, Guillaume Gardet a écrit :
>
>
> Le 15/11/2017 à 11:22, Guillaume Gardet a écrit :
>> Forgot to Cc ML. Done now.
>>
>>
>> Le 15/11/2017 à 11:14, Guillaume Gardet a écrit :
>>> Hello,
>>>
>>> I tested U-Boot v2017.09 on a Samsung Snow (Chromebook ARM) and while mmc0 (internal eMMC) is working fine, mmc1 (external SD slot) does not work.
>>> I get the following error for 'mmc dev 1' command:
>>>     mmc_init: -110, time 30
>
> Please also note that on boot (or on 1st 'mmc dev 1' cmd if I stop auto-boot), I firstly get:
>     mmc_init: -5, time 39
>
> Then, all next attempts retruns:
>     mmc_init: -110, time 30
>
>
> Guillaume
>
>
>>>
>>> Any idea what could be wrong?
>>>
>>> Guillaume
>>>
>>>
>>
>