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

[Lukasz Majewski]

On Thu, 16 Nov 2017 13:29:56 +0100
Guillaume Gardet <guillaume.gardet at free.fr> wrote:

> 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;

This seems like a workaround. The root cause of the problem is the
regression with HS 52MHz....

> 
>          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
> >>>
> >>>  
> >>  
> >  
> 
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Best regards,

Lukasz Majewski

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