Patchwork [2/2] mmc: dw_mmc: Give a good reset after we give power

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Submitter Douglas Anderson
Date Feb. 20, 2015, 6:57 p.m.
Message ID <1424458639-23330-2-git-send-email-dianders@chromium.org>
Download mbox | patch
Permalink /patch/5858281/
State New, archived
Headers show

Comments

Douglas Anderson - Feb. 20, 2015, 6:57 p.m.
We should give dw_mmc a good reset after we apply power.  On some
boards vqmmc may actually be connected to the IP block in the SoC so
it's good to reset after power comes in.

Without this we sometimes see failures enumerating cards on rk3288.

Signed-off-by: Doug Anderson <dianders@chromium.org>
---
 drivers/mmc/host/dw_mmc.c | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)
Jaehoon Chung - Feb. 25, 2015, 10:35 a.m.
Dear, Doug.

Looks good to me. Thanks!

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

Best Regards,
Jaehoon Chung

On 02/21/2015 03:57 AM, Doug Anderson wrote:
> We should give dw_mmc a good reset after we apply power.  On some
> boards vqmmc may actually be connected to the IP block in the SoC so
> it's good to reset after power comes in.
> 
> Without this we sometimes see failures enumerating cards on rk3288.
> 
> Signed-off-by: Doug Anderson <dianders@chromium.org>
> ---
>  drivers/mmc/host/dw_mmc.c | 27 ++++++++++++++++++---------
>  1 file changed, 18 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 43fcae1..6a712ae 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1119,13 +1119,23 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>  		mci_writel(slot->host, PWREN, regs);
>  		break;
>  	case MMC_POWER_ON:
> -		if (!IS_ERR(mmc->supply.vqmmc) && !slot->host->vqmmc_enabled) {
> -			ret = regulator_enable(mmc->supply.vqmmc);
> -			if (ret < 0)
> -				dev_err(slot->host->dev,
> -					"failed to enable vqmmc regulator\n");
> -			else
> +		if (!slot->host->vqmmc_enabled) {
> +			if (!IS_ERR(mmc->supply.vqmmc)) {
> +				ret = regulator_enable(mmc->supply.vqmmc);
> +				if (ret < 0)
> +					dev_err(slot->host->dev,
> +						"failed to enable vqmmc\n");
> +				else
> +					slot->host->vqmmc_enabled = true;
> +
> +			} else {
> +				/* Keep track so we don't reset again */
>  				slot->host->vqmmc_enabled = true;
> +			}
> +
> +			/* Reset our state machine after powering on */
> +			dw_mci_ctrl_reset(slot->host,
> +					  SDMMC_CTRL_ALL_RESET_FLAGS);
>  		}
>  
>  		/* Adjust clock / bus width after power is up */
> @@ -1139,10 +1149,9 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>  		if (!IS_ERR(mmc->supply.vmmc))
>  			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
>  
> -		if (!IS_ERR(mmc->supply.vqmmc) && slot->host->vqmmc_enabled) {
> +		if (!IS_ERR(mmc->supply.vqmmc) && slot->host->vqmmc_enabled)
>  			regulator_disable(mmc->supply.vqmmc);
> -			slot->host->vqmmc_enabled = false;
> -		}
> +		slot->host->vqmmc_enabled = false;
>  
>  		regs = mci_readl(slot->host, PWREN);
>  		regs &= ~(1 << slot->id);
> 

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Javier Martinez Canillas - Feb. 25, 2015, 6:26 p.m.
Hello Doug,

On 02/20/2015 07:57 PM, Doug Anderson wrote:
> We should give dw_mmc a good reset after we apply power.  On some
> boards vqmmc may actually be connected to the IP block in the SoC so
> it's good to reset after power comes in.
> 
> Without this we sometimes see failures enumerating cards on rk3288.
> 
> Signed-off-by: Doug Anderson <dianders@chromium.org>

On an Exynos5250 Snow, Exynos5420 Peach Pit and Exynos5800 Peach Pi:

Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>

Best regards,
Javier

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Patch

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 43fcae1..6a712ae 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1119,13 +1119,23 @@  static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 		mci_writel(slot->host, PWREN, regs);
 		break;
 	case MMC_POWER_ON:
-		if (!IS_ERR(mmc->supply.vqmmc) && !slot->host->vqmmc_enabled) {
-			ret = regulator_enable(mmc->supply.vqmmc);
-			if (ret < 0)
-				dev_err(slot->host->dev,
-					"failed to enable vqmmc regulator\n");
-			else
+		if (!slot->host->vqmmc_enabled) {
+			if (!IS_ERR(mmc->supply.vqmmc)) {
+				ret = regulator_enable(mmc->supply.vqmmc);
+				if (ret < 0)
+					dev_err(slot->host->dev,
+						"failed to enable vqmmc\n");
+				else
+					slot->host->vqmmc_enabled = true;
+
+			} else {
+				/* Keep track so we don't reset again */
 				slot->host->vqmmc_enabled = true;
+			}
+
+			/* Reset our state machine after powering on */
+			dw_mci_ctrl_reset(slot->host,
+					  SDMMC_CTRL_ALL_RESET_FLAGS);
 		}
 
 		/* Adjust clock / bus width after power is up */
@@ -1139,10 +1149,9 @@  static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 		if (!IS_ERR(mmc->supply.vmmc))
 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
 
-		if (!IS_ERR(mmc->supply.vqmmc) && slot->host->vqmmc_enabled) {
+		if (!IS_ERR(mmc->supply.vqmmc) && slot->host->vqmmc_enabled)
 			regulator_disable(mmc->supply.vqmmc);
-			slot->host->vqmmc_enabled = false;
-		}
+		slot->host->vqmmc_enabled = false;
 
 		regs = mci_readl(slot->host, PWREN);
 		regs &= ~(1 << slot->id);