[PATCH v6] mmc: dw_mmc: add quirk for broken data transfer over scheme

[Jaehoon Chung]

Hi, Heiko.

Is this patch based on ulf's tree?
At my dw-mmc tree, this patch can't apply..
So if you're ok, i will rework this patch about my dw-mmc tree.
how about?

Best Regards,
Jaehoon Chung

On 08/10/2015 08:12 PM, Heiko Stübner wrote:
> From: Addy Ke <addy.ke at rock-chips.com>
> 
> This patch add a new quirk to add a s/w timer to notify the driver
> to terminate current transfer and report a data timeout to the core,
> if DTO interrupt does NOT come within the given time.
> 
> dw_mmc call mmc_request_done func to finish transfer depends on
> DTO interrupt. If DTO interrupt does not come in sending data state,
> the current transfer will be blocked.
> 
> We got the reply from synopsys:
> There are two counters but both use the same value of [31:8] bits.
> Data timeout counter doesn't wait for stop clock and you should get
> DRTO even when the clock is not stopped.
> Host Starvation timeout counter is triggered with stop clock condition.
> 
> This means that host should get DRTO and DTO interrupt.
> 
> But this case really exists, when driver reads tuning data from
> card on RK3288-pink2 board. I measured waveforms by oscilloscope
> and found that card clock was always on and data lines were always
> holded high level in sending data state.
> 
> There are two possibility that data over interrupt doesn't come in
> reading data state on RK3X SoCs:
> - get command done interrupt, but doesn't get any data-related interrupt.
> - get data error interrupt, but doesn't get data over interrupt.
> 
> Signed-off-by: Addy Ke <addy.ke at rock-chips.com>
> 
> Address review comments from Jaehoon Chung.
> Signed-off-by: Heiko Stuebner <heiko at sntech.de>
> ---
> Changes in v2:
> - fix some typo.
> - remove extra timeout value (250ms).
> - remove dw_mci_dto_start_monitor func.
> - use "broken-dto" for new quirk and change Subject for it.
> 
> Changes in v3:
> - Remove dts for broken-dto, just add this quirk in dw_mci_rockchip_init
> 
> Changes in v4:
> - fix bug that may cause 32 bit overflow by (drto_clks * 1000).
> - doesn't call mod_timer in writing data state, becase TMOUT register only
>   for reading data.
> 
> Changes in v5:
> - fix some typo.
> - add a buffer for drto_ms.
> - move drto_ms related code to a helper function.
> 
> Changes in v6:
> - better spare time comment
> - let dw_mci_set_drto start the timer itself
> 
>  drivers/mmc/host/dw_mmc-rockchip.c |  3 ++
>  drivers/mmc/host/dw_mmc.c          | 64 
> ++++++++++++++++++++++++++++++++++++--
>  include/linux/mmc/dw_mmc.h         |  4 +++
>  3 files changed, 69 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mmc/host/dw_mmc-rockchip.c b/drivers/mmc/host/dw_mmc-
> rockchip.c
> index de15121..bc76aa2 100644
> --- a/drivers/mmc/host/dw_mmc-rockchip.c
> +++ b/drivers/mmc/host/dw_mmc-rockchip.c
> @@ -73,6 +73,9 @@ static int dw_mci_rockchip_init(struct dw_mci *host)
>  	/* It is slot 8 on Rockchip SoCs */
>  	host->sdio_id0 = 8;
>  
> +	/* It needs this quirk on all Rockchip SoCs */
> +	host->pdata->quirks |= DW_MCI_QUIRK_BROKEN_DTO;
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 4e95ca9..459e68b 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1528,6 +1528,20 @@ static int dw_mci_data_complete(struct dw_mci *host, 
> struct mmc_data *data)
>  	return data->error;
>  }
>  
> +static void dw_mci_set_drto(struct dw_mci *host)
> +{
> +	unsigned int drto_clks;
> +	unsigned int drto_ms;
> +
> +	drto_clks = mci_readl(host, TMOUT) >> 8;
> +	drto_ms = DIV_ROUND_UP(drto_clks, host->bus_hz / 1000);
> +
> +	/* add a bit spare time */
> +	drto_ms += 10;
> +
> +	mod_timer(&host->dto_timer, jiffies + msecs_to_jiffies(drto_ms));
> +}
> +
>  static void dw_mci_tasklet_func(unsigned long priv)
>  {
>  	struct dw_mci *host = (struct dw_mci *)priv;
> @@ -1605,8 +1619,16 @@ static void dw_mci_tasklet_func(unsigned long priv)
>  			}
>  
>  			if (!test_and_clear_bit(EVENT_XFER_COMPLETE,
> -						&host->pending_events))
> +						&host->pending_events)) {
> +				/*
> +				 * If all data-related interrupts don't come
> +				 * within the given time in reading data state.
> +				 */
> +				if ((host->quirks & DW_MCI_QUIRK_BROKEN_DTO) &&
> +				    (host->dir_status == DW_MCI_RECV_STATUS))
> +					dw_mci_set_drto(host);
>  				break;
> +			}
>  
>  			set_bit(EVENT_XFER_COMPLETE, &host->completed_events);
>  
> @@ -1639,8 +1661,17 @@ static void dw_mci_tasklet_func(unsigned long priv)
>  
>  		case STATE_DATA_BUSY:
>  			if (!test_and_clear_bit(EVENT_DATA_COMPLETE,
> -						&host->pending_events))
> +						&host->pending_events)) {
> +				/*
> +				 * If data error interrupt comes but data over
> +				 * interrupt doesn't come within the given time.
> +				 * in reading data state.
> +				 */
> +				if ((host->quirks & DW_MCI_QUIRK_BROKEN_DTO) &&
> +				    (host->dir_status == DW_MCI_RECV_STATUS))
> +					dw_mci_set_drto(host);
>  				break;
> +			}
>  
>  			host->data = NULL;
>  			set_bit(EVENT_DATA_COMPLETE, &host->completed_events);
> @@ -2201,6 +2232,9 @@ static irqreturn_t dw_mci_interrupt(int irq, void 
> *dev_id)
>  		}
>  
>  		if (pending & SDMMC_INT_DATA_OVER) {
> +			if (host->quirks & DW_MCI_QUIRK_BROKEN_DTO)
> +				del_timer(&host->dto_timer);
> +
>  			mci_writel(host, RINTSTS, SDMMC_INT_DATA_OVER);
>  			if (!host->data_status)
>  				host->data_status = pending;
> @@ -2593,6 +2627,28 @@ static void dw_mci_cmd11_timer(unsigned long arg)
>  	tasklet_schedule(&host->tasklet);
>  }
>  
> +static void dw_mci_dto_timer(unsigned long arg)
> +{
> +	struct dw_mci *host = (struct dw_mci *)arg;
> +
> +	switch (host->state) {
> +	case STATE_SENDING_DATA:
> +	case STATE_DATA_BUSY:
> +		/*
> +		 * If DTO interrupt does NOT come in sending data state,
> +		 * we should notify the driver to terminate current transfer
> +		 * and report a data timeout to the core.
> +		 */
> +		host->data_status = SDMMC_INT_DRTO;
> +		set_bit(EVENT_DATA_ERROR, &host->pending_events);
> +		set_bit(EVENT_DATA_COMPLETE, &host->pending_events);
> +		tasklet_schedule(&host->tasklet);
> +		break;
> +	default:
> +		break;
> +	}
> +}
> +
>  #ifdef CONFIG_OF
>  static struct dw_mci_of_quirks {
>  	char *quirk;
> @@ -2769,6 +2825,10 @@ int dw_mci_probe(struct dw_mci *host)
>  
>  	host->quirks = host->pdata->quirks;
>  
> +	if (host->quirks & DW_MCI_QUIRK_BROKEN_DTO)
> +		setup_timer(&host->dto_timer,
> +			    dw_mci_dto_timer, (unsigned long)host);
> +
>  	spin_lock_init(&host->lock);
>  	spin_lock_init(&host->irq_lock);
>  	INIT_LIST_HEAD(&host->queue);
> diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h
> index 5be9767..1c47ce3 100644
> --- a/include/linux/mmc/dw_mmc.h
> +++ b/include/linux/mmc/dw_mmc.h
> @@ -98,6 +98,7 @@ struct mmc_data;
>   * @irq_flags: The flags to be passed to request_irq.
>   * @irq: The irq value to be passed to request_irq.
>   * @sdio_id0: Number of slot0 in the SDIO interrupt registers.
> + * @dto_timer: Timer for broken data transfer over scheme.
>   *
>   * Locking
>   * =======
> @@ -204,6 +205,7 @@ struct dw_mci {
>  	int			sdio_id0;
>  
>  	struct timer_list       cmd11_timer;
> +	struct timer_list       dto_timer;
>  };
>  
>  /* DMA ops for Internal/External DMAC interface */
> @@ -226,6 +228,8 @@ struct dw_mci_dma_ops {
>  #define DW_MCI_QUIRK_HIGHSPEED			BIT(2)
>  /* Unreliable card detection */
>  #define DW_MCI_QUIRK_BROKEN_CARD_DETECTION	BIT(3)
> +/* Timer for broken data transfer over scheme */
> +#define DW_MCI_QUIRK_BROKEN_DTO			BIT(4)
>  
>  struct dma_pdata;
>  
>