Re: [PATCH 1/2] mmc: dw_mmc: Make sure we only adjust the clock when power is on

From: Jaehoon Chung
Date: Wed Feb 25 2015 - 05:34:55 EST


Hi, Doug.

It makes sense. Looks good to me. Thanks!

Acked-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx>

Best Regards,
Jaehoon Chung

On 02/21/2015 03:57 AM, Doug Anderson wrote:
> It appears that we can confuse things if we try to turn on the MMC
> clock when the power is off. Adjust is so that we turn the clock on
> (using dw_mci_setup_bus) after power is all the way on and we turn the
> clock off before the power goes off.
>
> Signed-off-by: Doug Anderson <dianders@xxxxxxxxxxxx>
> ---
> drivers/mmc/host/dw_mmc.c | 16 ++++++++++------
> 1 file changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 4d2e3c2..43fcae1 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1101,12 +1101,6 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> if (drv_data && drv_data->set_ios)
> drv_data->set_ios(slot->host, ios);
>
> - /* Slot specific timing and width adjustment */
> - dw_mci_setup_bus(slot, false);
> -
> - if (slot->host->state == STATE_WAITING_CMD11_DONE && ios->clock != 0)
> - slot->host->state = STATE_IDLE;
> -
> switch (ios->power_mode) {
> case MMC_POWER_UP:
> if (!IS_ERR(mmc->supply.vmmc)) {
> @@ -1133,8 +1127,15 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> else
> slot->host->vqmmc_enabled = true;
> }
> +
> + /* Adjust clock / bus width after power is up */
> + dw_mci_setup_bus(slot, false);
> +
> break;
> case MMC_POWER_OFF:
> + /* Turn clock off before power goes down */
> + dw_mci_setup_bus(slot, false);
> +
> if (!IS_ERR(mmc->supply.vmmc))
> mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
>
> @@ -1150,6 +1151,9 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> default:
> break;
> }
> +
> + if (slot->host->state == STATE_WAITING_CMD11_DONE && ios->clock != 0)
> + slot->host->state = STATE_IDLE;
> }
>
> static int dw_mci_card_busy(struct mmc_host *mmc)
>

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