Re: [PATCH V2 08/15] mmc: sdhci: add standard hw auto retuning support

[Adrian Hunter <adrian.hunter@intel.com>]

On 12/07/16 10:46, Dong Aisheng wrote:
> If HW supports SDHCI_TUNING_MODE_3 which is auto retuning, we won't
> retune during runtime suspend and resume, instead we use Re-tuning
> Request signaled via SDHCI_INT_RETUNE interrupt to do retuning and
> hw auto retuning during data transfer to guarantee the signal sample
> window correction.
> 
> This can avoid a mass of repeatedly retuning during small file system
> data access and improve the performance.
> 
> Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>


Acked-by: Adrian Hunter <adrian.hunter@intel.com>


> ---
>  drivers/mmc/host/sdhci.c | 15 ++++++++++++---
>  drivers/mmc/host/sdhci.h |  3 +++
>  2 files changed, 15 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 7894652b9929..31c14b0ff8e2 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -229,6 +229,10 @@ static void sdhci_init(struct sdhci_host *host, int soft)
>  		    SDHCI_INT_TIMEOUT | SDHCI_INT_DATA_END |
>  		    SDHCI_INT_RESPONSE;
>  
> +	if (host->tuning_mode == SDHCI_TUNING_MODE_2 ||
> +	    host->tuning_mode == SDHCI_TUNING_MODE_3)
> +		host->ier |= SDHCI_INT_RETUNE;
> +
>  	sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
>  	sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
>  
> @@ -2673,6 +2677,9 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id)
>  			pr_err("%s: Card is consuming too much power!\n",
>  				mmc_hostname(host->mmc));
>  
> +		if (intmask & SDHCI_INT_RETUNE)
> +			mmc_retune_needed(host->mmc);
> +
>  		if (intmask & SDHCI_INT_CARD_INT) {
>  			sdhci_enable_sdio_irq_nolock(host, false);
>  			host->thread_isr |= SDHCI_INT_CARD_INT;
> @@ -2682,7 +2689,7 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id)
>  		intmask &= ~(SDHCI_INT_CARD_INSERT | SDHCI_INT_CARD_REMOVE |
>  			     SDHCI_INT_CMD_MASK | SDHCI_INT_DATA_MASK |
>  			     SDHCI_INT_ERROR | SDHCI_INT_BUS_POWER |
> -			     SDHCI_INT_CARD_INT);
> +			     SDHCI_INT_RETUNE | SDHCI_INT_CARD_INT);
>  
>  		if (intmask) {
>  			unexpected |= intmask;
> @@ -2787,7 +2794,8 @@ int sdhci_suspend_host(struct sdhci_host *host)
>  	sdhci_disable_card_detection(host);
>  
>  	mmc_retune_timer_stop(host->mmc);
> -	mmc_retune_needed(host->mmc);
> +	if (host->tuning_mode != SDHCI_TUNING_MODE_3)
> +		mmc_retune_needed(host->mmc);
>  
>  	if (!device_may_wakeup(mmc_dev(host->mmc))) {
>  		host->ier = 0;
> @@ -2848,7 +2856,8 @@ int sdhci_runtime_suspend_host(struct sdhci_host *host)
>  	unsigned long flags;
>  
>  	mmc_retune_timer_stop(host->mmc);
> -	mmc_retune_needed(host->mmc);
> +	if (host->tuning_mode != SDHCI_TUNING_MODE_3)
> +		mmc_retune_needed(host->mmc);
>  
>  	spin_lock_irqsave(&host->lock, flags);
>  	host->ier &= SDHCI_INT_CARD_INT;
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index e241e11a90d0..0411c9f36461 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -128,6 +128,7 @@
>  #define  SDHCI_INT_CARD_INSERT	0x00000040
>  #define  SDHCI_INT_CARD_REMOVE	0x00000080
>  #define  SDHCI_INT_CARD_INT	0x00000100
> +#define  SDHCI_INT_RETUNE	0x00001000
>  #define  SDHCI_INT_ERROR	0x00008000
>  #define  SDHCI_INT_TIMEOUT	0x00010000
>  #define  SDHCI_INT_CRC		0x00020000
> @@ -518,6 +519,8 @@ struct sdhci_host {
>  	unsigned int		tuning_count;	/* Timer count for re-tuning */
>  	unsigned int		tuning_mode;	/* Re-tuning mode supported by host */
>  #define SDHCI_TUNING_MODE_1	0
> +#define SDHCI_TUNING_MODE_2	1
> +#define SDHCI_TUNING_MODE_3	2
>  
>  	unsigned long private[0] ____cacheline_aligned;
>  };
>