Hi, Addy.

On 01/05/2015 05:21 PM, Addy Ke wrote:
> 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.
> 
> We don't know why we have this problem, but we need it to fix this problem 
> now.
> And I will post a follow up change when we find the root cause.
> 
> Signed-off-by: Addy Ke <addy...@rock-chips.com>
> ---
> 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.
> 
>  drivers/mmc/host/dw_mmc-rockchip.c |  3 ++
>  drivers/mmc/host/dw_mmc.c          | 71 
> ++++++++++++++++++++++++++++++++++++--
>  include/linux/mmc/dw_mmc.h         |  5 +++
>  3 files changed, 77 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mmc/host/dw_mmc-rockchip.c 
> b/drivers/mmc/host/dw_mmc-rockchip.c
> index 5650ac4..ba92ebd 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 6e4d864..ace4b40 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1468,6 +1468,20 @@ static int dw_mci_data_complete(struct dw_mci *host, 
> struct mmc_data *data)
>       return data->error;
>  }
>  
> +static unsigned int dw_mci_get_drto_ms(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 buffer */
> +     drto_ms += 10;

Add a buffer? What means?

> +
> +     return drto_ms;
> +}

dw_mci_set_drto() instead of dw_mci_get_drto_ms().

Then you can include the codes relevant to broken-dto.

static unsigned int (or void) dw_mci_set_drto(struct dw_mci *host) {

        if (!(host->quirks & DW_MCI_QUIRK_BROKEN_DTO))
                return;

        ... 
        add codes relevant to broken-dtop (mod_timer) at here.
}

If you need to start timer, you have only to call dw_mci_set_drto().
how about?

Best Regards,
Jaehoon Chung

> +
>  static void dw_mci_tasklet_func(unsigned long priv)
>  {
>       struct dw_mci *host = (struct dw_mci *)priv;
> @@ -1477,6 +1491,7 @@ static void dw_mci_tasklet_func(unsigned long priv)
>       enum dw_mci_state state;
>       enum dw_mci_state prev_state;
>       unsigned int err;
> +     unsigned int drto_ms;
>  
>       spin_lock(&host->lock);
>  
> @@ -1542,8 +1557,19 @@ 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)) {
> +                                     drto_ms = dw_mci_get_drto_ms(host);
> +                                     mod_timer(&host->dto_timer, jiffies +
> +                                               msecs_to_jiffies(drto_ms));
> +                             }
>                               break;
> +                     }
>  
>                       set_bit(EVENT_XFER_COMPLETE, &host->completed_events);
>  
> @@ -1573,8 +1599,20 @@ 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)) {
> +                                     drto_ms = dw_mci_get_drto_ms(host);
> +                                     mod_timer(&host->dto_timer, jiffies +
> +                                               msecs_to_jiffies(drto_ms));
> +                             }
>                               break;
> +                     }
>  
>                       host->data = NULL;
>                       set_bit(EVENT_DATA_COMPLETE, &host->completed_events);
> @@ -2135,6 +2173,9 @@ 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;
> @@ -2522,6 +2563,28 @@ ciu_out:
>       return ret;
>  }
>  
> +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;
> @@ -2670,6 +2733,10 @@ 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 471fb31..2ece0dd 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
>   * =======
> @@ -202,6 +203,8 @@ struct dw_mci {
>       int                     irq;
>  
>       int                     sdio_id0;
> +
> +     struct timer_list       dto_timer;
>  };
>  
>  /* DMA ops for Internal/External DMAC interface */
> @@ -226,6 +229,8 @@ struct dw_mci_dma_ops {
>  #define DW_MCI_QUIRK_BROKEN_CARD_DETECTION   BIT(3)
>  /* No write protect */
>  #define DW_MCI_QUIRK_NO_WRITE_PROTECT                BIT(4)
> +/* Timer for broken data transfer over scheme */
> +#define DW_MCI_QUIRK_BROKEN_DTO                      BIT(5)
>  
>  /* Slot level quirks */
>  /* This slot has no write protect */
> 

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