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

Heiko Stübner heiko at sntech.de
Mon Aug 10 12:07:41 PDT 2015


Hi Jaehoon,

Am Dienstag, 11. August 2015, 01:26:52 schrieb 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.

looks I'm to late to comment, so thanks for adapting the patch and including 
it in your pull request :-)


Thanks
Heiko

> 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;




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