On 13 August 2012 11:19, Dmitry Rozhkov <dmitry.rozh...@jollamobile.com> wrote:
> According to p6.4.1.1 of the Physical Layer Simplified Specification
> Ver3.01 the "host needs to keep power line level less than 0.5V and
> more than 1ms before power ramp up". This patch adds an explicit delay
> of 10ms just before power rump up.
>
> Without this patch some microSD cards (e.g. Kingston 8G Class 10) can't be
> used as bootable media on some TI OMAP chips at least.
> See https://bugs.nemomobile.org/show_bug.cgi?id=92 for details.
>
> Signed-off-by: Dmitry Rozhkov <dmitry.rozh...@jollamobile.com>
> ---
> drivers/mmc/core/core.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 0b6141d..22b0eb2 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -1163,6 +1163,13 @@ static void mmc_power_up(struct mmc_host *host)
>
> mmc_host_clk_hold(host);
>
> + /*
> + * According to p6.4.1.1 of the Physical Layer Simplified
> Specification
> + * Ver3.01 the "host needs to keep power line level less than 0.5V and
> + * more than 1ms before power ramp up".
> + */
> + mmc_delay(10);
can you instead just try giving this delay in mmc_start_host as a
parameter to mmc_detect_change.
> +
> /* If ocr is set, we use it */
> if (host->ocr)
> bit = ffs(host->ocr) - 1;
> --
> 1.7.9.5
>
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