Hi,
On 05/24/2016 06:07 PM, 장민우 wrote:
> Dear linux-mmc.
>
> Hello, I'm Minwoo Jang.
>
> I have a question about using default speed of the eMMC.
>
> When default speed is used, mmc_select_bus_width() is never called.
>
> So, eMMC can not be set 4 bit or 8 bit bus width, I think.
>
> Please, give me your opinions on the following diff codes.
In mmc_select_timing(), timing should be set to MMC_TIMING_HS or others.
Then mmc_select_bus_width() should be entered.
Best Regards,
Jaehoon Chung
>
> Thank you.
>
> =====================================================
>
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 94b4462..3b1cc4d 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -952,6 +952,8 @@ static int mmc_select_bus_width(struct mmc_card *card)
>
> if (!err) {
> err = bus_width;
> + pr_warn("%s: switch to bus width %d\n",
> + mmc_hostname(host), (1 << bus_width));
> break;
> } else {
> pr_warn("%s: switch to bus width %d failed\n",
> @@ -1500,6 +1502,14 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
> if (err)
> goto err;
> }
> + } else {
> + /* Select the bus width for normal speed mode */
> + err = mmc_select_bus_width(card);
> + if (IS_ERR_VALUE(err)) {
> + pr_warn("%s: Selecting bus width failed\n",
> + mmc_hostname(card->host));
> + goto err;
> + }
> }
>
> Best regards,
>
> MW Jang.
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