Re: [PATCH] mmc: dw_mmc: enable controller interrupt before calling mmc_start_host

[Jaehoon Chung <jh80.chung@samsung.com>]

Hi All,

Well, i didn't find the James's error message.
But i confused about the clock value.

Bus speed : 99840000Hz
request   : 200000Hz
Div : 250

If bus_speed is divided with div, then actual value should be 399360Hz.
But this log is produced 199680Hz. What's wrong?

I think this message can be confused to debug.

Best Regards,
Jaehoon Chung

On 11/20/2012 06:39 PM, James Hogan wrote:
> Hi Yuvaraj,
> 
> On 20/11/12 05:35, Yuvaraj Kumar wrote:
>> Its not sufficient.In my case, sdio_reset command was submitted to
>> dw_mmc controller before interrupts are enabled.
>> By looking at your log,it seems something wrong with frequency set by
>> your U-boot.
> 
> I'm not using U-boot, I'm booting with JTAG. In any case it works if I
> revert your patch so I think the clocks are fine. I'll continue
> debugging it and see if I can figure out what's happening.
> 
> Cheers
> James
> 
>>
>> Best Regards
>> Yuvaraj
>>
>> On Mon, Nov 19, 2012 at 6:50 PM, James Hogan <james.hogan@imgtec.com> wrote:
>>> On 19/11/12 13:01, Yuvaraj CD wrote:
>>>> As mmc_start_host is getting called before enabling the dw_mmc controller
>>>> interrupt, there is a problem of missing the SDMMC_INT_CMD_DONE for the
>>>> very first command sent by the sdio_reset.
>>>> This problem occurs only when we disable MMC debugging i.e, MMC_DEBUG [=n].
>>>> Hence this patch enables the dw_mmc controller interrupt before mmc_start_host.
>>>>
>>>> Signed-off-by: Yuvaraj CD <yuvaraj.cd@samsung.com>
>>>
>>> Hi Yuvaraj,
>>>
>>> I get the following errors after this patch is applied
>>> (2da1d7f2948900cd50d38643db39f790edb3cc96, merged in v3.7-rc5) and the
>>> driver doesn't work as a result. Reverting it fixes the problem.
>>>
>>> mmc0: error -110 whilst initialising SD card
>>> mmc_host mmc0: Bus speed (slot 0) = 99840000Hz (slot req 300000Hz, actual 298922HZ div = 167)
>>> mmc0: error -110 whilst initialising SD card
>>> mmc_host mmc0: Bus speed (slot 0) = 99840000Hz (slot req 200000Hz, actual 199680HZ div = 250)
>>> mmc0: error -110 whilst initialising SD card
>>> mmc_host mmc0: Bus speed (slot 0) = 99840000Hz (slot req 195765Hz, actual 195764HZ div = 255)
>>> mmc0: error -110 whilst initialising SD card
>>> mmc_host mmc0: Bus speed (slot 0) = 99840000Hz (slot req 400000Hz, actual 399360HZ div = 125)
>>> mmc0: error -110 whilst initialising SD card
>>> mmc_host mmc0: Bus speed (slot 0) = 99840000Hz (slot req 300000Hz, actual 298922HZ div = 167)
>>> mmc0: error -110 whilst initialising SD card
>>> mmc_host mmc0: Bus speed (slot 0) = 99840000Hz (slot req 200000Hz, actual 199680HZ div = 250)
>>> mmc0: error -110 whilst initialising SD card
>>> mmc_host mmc0: Bus speed (slot 0) = 99840000Hz (slot req 195765Hz, actual 195764HZ div = 255)
>>> mmc0: error -110 whilst initialising SD card
>>>
>>> The interrupts are already cleared and disabled at the beginning of the
>>> probe function, so is the following sufficient (after reverting your
>>> patch) to fix the problem you've been observing?
>>>
>>> Thanks
>>> James
>>>
>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>>> index ec9b5a8..2be9899 100644
>>> --- a/drivers/mmc/host/dw_mmc.c
>>> +++ b/drivers/mmc/host/dw_mmc.c
>>> @@ -2266,7 +2266,6 @@ int dw_mci_probe(struct dw_mci *host)
>>>          * Enable interrupts for command done, data over, data empty, card det,
>>>          * receive ready and error such as transmit, receive timeout, crc error
>>>          */
>>> -       mci_writel(host, RINTSTS, 0xFFFFFFFF);
>>>         mci_writel(host, INTMASK, SDMMC_INT_CMD_DONE | SDMMC_INT_DATA_OVER |
>>>                    SDMMC_INT_TXDR | SDMMC_INT_RXDR |
>>>                    DW_MCI_ERROR_FLAGS | SDMMC_INT_CD);
>>>
>>>
>>>> ---
>>>>  drivers/mmc/host/dw_mmc.c |   29 +++++++++++++++--------------
>>>>  1 file changed, 15 insertions(+), 14 deletions(-)
>>>>
>>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>>>> index a23af77..729c031 100644
>>>> --- a/drivers/mmc/host/dw_mmc.c
>>>> +++ b/drivers/mmc/host/dw_mmc.c
>>>> @@ -2233,6 +2233,21 @@ int dw_mci_probe(struct dw_mci *host)
>>>>         else
>>>>                 host->num_slots = ((mci_readl(host, HCON) >> 1) & 0x1F) + 1;
>>>>
>>>> +       /*
>>>> +        * Enable interrupts for command done, data over, data empty, card det,
>>>> +        * receive ready and error such as transmit, receive timeout, crc error
>>>> +        */
>>>> +       mci_writel(host, RINTSTS, 0xFFFFFFFF);
>>>> +       mci_writel(host, INTMASK, SDMMC_INT_CMD_DONE | SDMMC_INT_DATA_OVER |
>>>> +                  SDMMC_INT_TXDR | SDMMC_INT_RXDR |
>>>> +                  DW_MCI_ERROR_FLAGS | SDMMC_INT_CD);
>>>> +       mci_writel(host, CTRL, SDMMC_CTRL_INT_ENABLE); /* Enable mci
>>>> interrupt */
>>>> +
>>>> +       dev_info(host->dev, "DW MMC controller at irq %d, "
>>>> +                "%d bit host data width, "
>>>> +                "%u deep fifo\n",
>>>> +                host->irq, width, fifo_size);
>>>> +
>>>>         /* We need at least one slot to succeed */
>>>>         for (i = 0; i < host->num_slots; i++) {
>>>>                 ret = dw_mci_init_slot(host, i);
>>>> @@ -2262,20 +2277,6 @@ int dw_mci_probe(struct dw_mci *host)
>>>>         else
>>>>                 host->data_offset = DATA_240A_OFFSET;
>>>>
>>>> -       /*
>>>> -        * Enable interrupts for command done, data over, data empty, card det,
>>>> -        * receive ready and error such as transmit, receive timeout, crc error
>>>> -        */
>>>> -       mci_writel(host, RINTSTS, 0xFFFFFFFF);
>>>> -       mci_writel(host, INTMASK, SDMMC_INT_CMD_DONE | SDMMC_INT_DATA_OVER |
>>>> -                  SDMMC_INT_TXDR | SDMMC_INT_RXDR |
>>>> -                  DW_MCI_ERROR_FLAGS | SDMMC_INT_CD);
>>>> -       mci_writel(host, CTRL, SDMMC_CTRL_INT_ENABLE); /* Enable mci
>>>> interrupt */
>>>> -
>>>> -       dev_info(host->dev, "DW MMC controller at irq %d, "
>>>> -                "%d bit host data width, "
>>>> -                "%u deep fifo\n",
>>>> -                host->irq, width, fifo_size);
>>>>         if (host->quirks & DW_MCI_QUIRK_IDMAC_DTO)
>>>>                 dev_info(host->dev, "Internal DMAC interrupt fix enabled.\n");
>>>>
>>>> --
>>>> 1.7.9.5
>>>>
>>>> --
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>>>>
>>>>
>>>> --
>>>> James Hogan
>>>>
>>>
> 
>