Re: [PATCH] mmc: dw_mmc: add quirk for data over interrupt timeout

From: addy ke
Date: Wed Nov 19 2014 - 00:57:21 EST

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In reply to: Jaehoon Chung: "Re: [PATCH] mmc: dw_mmc: add quirk for data over interrupt timeout"
Next in thread: addy ke: "Re: [PATCH] mmc: dw_mmc: add quirk for data over interrupt timeout"
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Hi Jaehoon

On 2014/11/19 09:22, Jaehoon Chung Wrote:
> Hi, Addy.
>
> On 11/18/2014 09:32 AM, Addy wrote:
>>
>> On 2014å11æ14æ 21:18, Jaehoon Chung wrote:
>>> 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.
>>
>> DW_MCI_QUIRK_IDMAC_DTO is only for version2.0 or below.
>> /*
>> * DTO fix - version 2.10a and below, and only if internal DMA
>> * is configured.
>> */
>> if (host->quirks & DW_MCI_QUIRK_IDMAC_DTO) {
>> if (!pending &&
>> ((mci_readl(host, STATUS) >> 17) & 0x1fff))
>> pending |= SDMMC_INT_DATA_OVER;
>> }
>>
>> It meams that if interrupt comes, but pending = 0 && FIFO_COUNT(bit17-29) !=0,
>> then force to set SDMMC_INT_DATA_OVER.
>> But in our case, FIFO_COUNT = 0 (STATUS register value is 0xad06). This is
>> because that the card does not send data to host. So there is no interrupts come,
>> and interrupt handle function(dw_mci_interrupt) will not be called. So we need a
>> timer to handle this case.
>>
>> So I think SDMMC_INT_DATA_OVER is not suitable for this case, and we need a new
>> 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@xxxxxxxxxxxxxx>
>>>>
>>>> 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@xxxxxxxxxxxxxx>
>>>> ---
>>>> 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;
>
> What's 250? And how about using the DIV_ROUND_UP?
>
250ms is only for more timeout.
maybe data timeout read from TMOUT register is enough.
So, I will remove 250.
new code:
data_tmout_clks = (mci_readl(host, TMOUT) >> 8);
data_tmout_ms = DIV_ROUND_UP(data_tmout_clks * 100, host->bus_hz);
Is right?

>>>> +
>>>> + 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);
>
> if timer is starting at only here, dw_mci_dto_start_monitor() doesn't need.
>
Ok, I will change it in the next patch.
>>>> 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;
>
> I prefer to use the "data" instead of "arg"
>
Ok, I will change it in the next patch.
>>>> +
>>>> + 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
> teminate/terminate?
>
Am, I will change it in the next patch.
>>>> + * 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);
>
> Dose it need to set EVENT_DATA_COMPLETE?
>
Yes, it is nessarry!
If not, dw_mci_data_complete function will not be called in my test.
Analysis as follows:
After host recevied command response, driver call tasklet_schedule to
set EVENT_CMD_COMPLETE, change state to STATE_SENDING_DATA, and call
mod_timer. Because there is no any interrupts come in this case,
tasklet_schedule function will not be called until dw_mci_timer is called.

dw_mci_timer-->
tasklet_schedule-->
dw_mci_tasklet_func-->
state == STATE_SENDING_DATA and EVENT_DATA_ERROR-->
dw_mci_stop_dma, set EVENT_XFER_COMPLETE, send_stop_abort, state = STATE_DATA_ERROR, and then break;-->
check state again -->
state == STATE_DATA_ERROR, if it NOT set EVENT_DATA_COMPLETE in dw_mci_timer goto 1), else goto 2) -->

1) in case STATE_DATA_BUSY, there does nothing but break, and dw_mci_data_complete and dw_mci_request_end
will not be called. then mmc blocks.

2) in case STATE_DATA_BUSY, becase EVENT_DATA_COMPLETE is set, dw_mci_data_complete and dw_mci_request_end
will be called to report error to the core.

>>>> + 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,
>>>> },
>
> Well, this is s/w timer, so i'm not sure this can be merged into dt-file.
> If this is generic solution, we can add s/w timer by default. how about?
ok, I will change it in the next patch.

And is there somewhere need to call del_timer?
>
> Best Regards,
> Jaehoon Chung
>
>>>> };
>>>> @@ -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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>> linux-arm-kernel mailing list
>> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
>
>
>

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Next message: Namhyung Kim: "Re: [PATCH V3 3/3] perf tools: Construct LBR call chain"
Previous message: Robin Gong: "Re: [PATCH 1/3] ARM: dts: imx6: add pm_power_off support for i.mx6 chips"
In reply to: Jaehoon Chung: "Re: [PATCH] mmc: dw_mmc: add quirk for data over interrupt timeout"
Next in thread: addy ke: "Re: [PATCH] mmc: dw_mmc: add quirk for data over interrupt timeout"
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