[U-Boot] [U-BOOT] mmc: sdhci: Enable 8-bit bus width only for 3.0 spec onwards

[Jagan Teki]

Any help on this, was this a useful fix.

Thanks,
Jagan.

On Mon, May 27, 2013 at 10:49 AM, Jagannadha Sutradharudu Teki
<jagannadha.sutradharudu-teki at xilinx.com> wrote:
> Request for an update on this.
>
> Thanks,
> Jagan.
>
>> -----Original Message-----
>> From: Jagannadha Sutradharudu Teki [mailto:jagannadha.sutradharudu-
>> teki at xilinx.com]
>> Sent: 21 May 2013 15:02
>> To: u-boot at lists.denx.de
>> Cc: monstr at monstr.eu; Andy Fleming; Jagannadha Sutradharudu Teki
>> Subject: [U-BOOT] mmc: sdhci: Enable 8-bit bus width only for 3.0 spec onwards
>>
>> CAP register don't have any information for 8-bit buswidth support on 2.0 sdhci
>> spec, only from 3.0 onwards bit[18] got this information.
>>
>> Due to this misassignment in sdhci, mmc is setting 8-bit buswidth using
>> mmc_set_bus_width even if controller doesn't support.
>> Below change has code information.
>> "mmc: Properly determine maximum supported bus width"
>> (sha1: 7798f6dbd5e1a3030ed81a81da5dfb57c3307cac)
>>
>> Bug log: <mmc plus and emmc cards)
>> -------
>> zynq-uboot> mmcinfo
>> Error detected in status(0x208100)!
>> Device: zynq_sdhci
>> Manufacturer ID: fe
>> .....
>>
>> So enable 8-bit support only for 3.0 spec using CAP and for below 3.0 assign
>> mmc->host_caps = MMC_MODE_8BIT on respective platform driver if host have
>> a support.
>>
>> Signed-off-by: Jagannadha Sutradharudu Teki <jaganna at xilinx.com>
>> ---
>>  drivers/mmc/sdhci.c |    6 ++++--
>>  1 files changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c index 1eaea04..c5631bf
>> 100644
>> --- a/drivers/mmc/sdhci.c
>> +++ b/drivers/mmc/sdhci.c
>> @@ -486,8 +486,10 @@ int add_sdhci(struct sdhci_host *host, u32 max_clk,
>> u32 min_clk)
>>               mmc->voltages |= host->voltages;
>>
>>       mmc->host_caps = MMC_MODE_HS | MMC_MODE_HS_52MHz |
>> MMC_MODE_4BIT;
>> -     if (caps & SDHCI_CAN_DO_8BIT)
>> -             mmc->host_caps |= MMC_MODE_8BIT;
>> +     if ((host->version & SDHCI_SPEC_VER_MASK) >= SDHCI_SPEC_300) {
>> +             if (caps & SDHCI_CAN_DO_8BIT)
>> +                     mmc->host_caps |= MMC_MODE_8BIT;
>> +     }
>>       if (host->host_caps)
>>               mmc->host_caps |= host->host_caps;
>>
>> --
>> 1.7.4
>>
>
>
>
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-- 
--
Thanks,
Jagan.