[PATCH] mmc: dw_mmc: add quirk for data over interrupt timeout
Jaehoon Chung
jh80.chung at samsung.com
Fri Nov 14 05:18:24 PST 2014
Hi, Addy.
Did you use the DW_MCI_QUIRK_IDMAC_DTO?
I'm not sure, but i wonder if you get what result when you use above quirk.
And i will check more this patch at next week.
Thanks for your efforts.
Best Regards,
Jaehoon Chung
On 11/14/2014 10:05 PM, Addy Ke wrote:
> From: Addy <addy.ke at rock-chips.com>
>
> This patch add a new quirk to notify the driver to teminate
> current transfer and report a data timeout to the core,
> if data over interrupt does NOT come within the given time.
>
> dw_mmc call mmc_request_done func to finish transfer depends on
> data over interrupt. If data over interrupt does not come in
> sending data state, the current transfer will be blocked.
>
> 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. This is the cause that
> card does NOT send data to host.
>
> According to synopsys designware databook, the timeout counter is
> started only after the card clock is stopped.
>
> So if card clock is always on, data read timeout interrupt will NOT come,
> and if data lines are always holded high level, all data-related
> interrupt such as start-bit error, data crc error, data over interrupt,
> end-bit error, and so on, will NOT come too.
>
> So driver can't get the current state, it can do nothing but wait for.
>
> This patch is based on https://patchwork.kernel.org/patch/5227941/
>
> Signed-off-by: Addy <addy.ke at rock-chips.com>
> ---
> drivers/mmc/host/dw_mmc.c | 47 +++++++++++++++++++++++++++++++++++++++++++++-
> include/linux/mmc/dw_mmc.h | 5 +++++
> 2 files changed, 51 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index b4c3044..3960fc3 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1448,6 +1448,17 @@ static int dw_mci_data_complete(struct dw_mci *host, struct mmc_data *data)
> return data->error;
> }
>
> +static inline void dw_mci_dto_start_monitor(struct dw_mci *host)
> +{
> + unsigned int data_tmout_clks;
> + unsigned int data_tmout_ms;
> +
> + data_tmout_clks = (mci_readl(host, TMOUT) >> 8);
> + data_tmout_ms = (data_tmout_clks * 1000 / host->bus_hz) + 250;
> +
> + mod_timer(&host->dto_timer, jiffies + msecs_to_jiffies(data_tmout_ms));
> +}
> +
> static void dw_mci_tasklet_func(unsigned long priv)
> {
> struct dw_mci *host = (struct dw_mci *)priv;
> @@ -1522,8 +1533,11 @@ static void dw_mci_tasklet_func(unsigned long priv)
> }
>
> if (!test_and_clear_bit(EVENT_XFER_COMPLETE,
> - &host->pending_events))
> + &host->pending_events)) {
> + if (host->quirks & DW_MCI_QUIRK_DTO_TIMER)
> + dw_mci_dto_start_monitor(host);
> break;
> + }
>
> set_bit(EVENT_XFER_COMPLETE, &host->completed_events);
>
> @@ -2115,6 +2129,9 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
> }
>
> if (pending & SDMMC_INT_DATA_OVER) {
> + if (host->quirks & DW_MCI_QUIRK_DTO_TIMER)
> + del_timer(&host->dto_timer);
> +
> mci_writel(host, RINTSTS, SDMMC_INT_DATA_OVER);
> if (!host->data_status)
> host->data_status = pending;
> @@ -2502,6 +2519,28 @@ 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 data over interrupt does NOT come in sending data state,
> + * we should notify the driver to teminate 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;
> @@ -2513,6 +2552,9 @@ static struct dw_mci_of_quirks {
> }, {
> .quirk = "disable-wp",
> .id = DW_MCI_QUIRK_NO_WRITE_PROTECT,
> + }, {
> + .quirk = "dto-timer",
> + .id = DW_MCI_QUIRK_DTO_TIMER,
> },
> };
>
> @@ -2654,6 +2696,9 @@ int dw_mci_probe(struct dw_mci *host)
>
> spin_lock_init(&host->lock);
> INIT_LIST_HEAD(&host->queue);
> + if (host->quirks & DW_MCI_QUIRK_DTO_TIMER)
> + setup_timer(&host->dto_timer,
> + dw_mci_dto_timer, (unsigned long)host);
>
> /*
> * Get the host data width - this assumes that HCON has been set with
> diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h
> index 42b724e..2477813 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 data over interrupt timeout.
> *
> * Locking
> * =======
> @@ -196,6 +197,8 @@ struct dw_mci {
> int irq;
>
> int sdio_id0;
> +
> + struct timer_list dto_timer;
> };
>
> /* DMA ops for Internal/External DMAC interface */
> @@ -220,6 +223,8 @@ 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 data over interrupt timeout */
> +#define DW_MCI_QUIRK_DTO_TIMER BIT(5)
>
> /* Slot level quirks */
> /* This slot has no write protect */
>
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