Re: [PATCH v2 8/8] mmc: core: use the broken-cd for non-removable card

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

On 01/28/2014 08:21 PM, Ulf Hansson wrote:
> On 28 January 2014 11:51, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>> Dear, Ulf.
>>
>> On 01/28/2014 07:32 PM, Ulf Hansson wrote:
>>> On 28 January 2014 09:24, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>>>> Some SoC is used the broken card-detection.
>>>> And it should be also used the "non-removable".
>>>> Even if card is "non-removable", it didn't always use the cd-gpio.
>>>>
>>>> If it's used only broken-cd, then card-detect interrupt is polling.
>>>>
>>>> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
>>>> ---
>>>>  drivers/mmc/core/core.c |    4 ++--
>>>>  drivers/mmc/core/host.c |    6 +++---
>>>>  2 files changed, 5 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
>>>> index 098374b..df732aa 100644
>>>> --- a/drivers/mmc/core/core.c
>>>> +++ b/drivers/mmc/core/core.c
>>>> @@ -2460,8 +2460,8 @@ void mmc_rescan(struct work_struct *work)
>>>>          */
>>>>         mmc_bus_put(host);
>>>>
>>>> -       if (!(host->caps & MMC_CAP_NONREMOVABLE) && host->ops->get_cd &&
>>>> -                       host->ops->get_cd(host) == 0) {
>>>> +       if (host->ops->get_cd && host->ops->get_cd(host) == 0 &&
>>>> +                       !(host->caps & MMC_CAP_NONREMOVABLE)) {
>>>
>>> What's the difference here?
>>
>> eMMC is non-removable card. So i added the "non-removable" property at dt file.
>> Then first checking !(host->caps & MMC_CAP_NONREMOVABLE), and didn't call get_cd().
>> In case of dw-mmc.c, after calling get_cd(), CARD_PRESENT bit is set at dw_mci_get_cd().
>> I didn't check other driver how it work.
>> If you didn't this change, i will change the dw-mmc controller.
> 
> Thanks for the clarification.
> 
> I would then suggest you to change in dw-mmc instead, since I think
> using the MMC_CAP_NONREMOVABLE flag, indicates that the .get_cd
> callback is not needed.

It's reasonable. I will consider to change this into dw_mmc.c.

Best Regards,
Jaehoon Chung

> 
> Kind regards
> Ulf Hansson
> 
>>
>>>
>>>>                 mmc_claim_host(host);
>>>>                 mmc_power_off(host);
>>>>                 mmc_release_host(host);
>>>> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
>>>> index 4b81c93..52a64fe 100644
>>>> --- a/drivers/mmc/core/host.c
>>>> +++ b/drivers/mmc/core/host.c
>>>> @@ -356,6 +356,9 @@ int mmc_of_parse(struct mmc_host *host)
>>>>          * configuration is performed.
>>>>          */
>>>>
>>>> +       if (of_find_property(np, "broken-cd", &len))
>>>> +               host->caps |= MMC_CAP_NEEDS_POLL;
>>>> +
>>>
>>> No. There are no meaning in using MMC_CAP_NEEDS_POLL in conjunction
>>> with MMC_CAP_NONREMOVABLE.
>>>
>>> Using MMC_CAP_NONREMOVABLE, will allow mmc_rescan to detect a card  -
>>> only for one iteration. Thus MMC_CAP_NEEDS_POLL will have no effect.
>>
>> Sorry. You're right. It's no meaning. I will maintain the original code.
>>
>> Best Regards,
>> Jaehoon Chung
>>>
>>> Kind regards
>>> Uffe
>>>
>>>
>>>>         /* Parse Card Detection */
>>>>         if (of_find_property(np, "non-removable", &len)) {
>>>>                 host->caps |= MMC_CAP_NONREMOVABLE;
>>>> @@ -364,9 +367,6 @@ int mmc_of_parse(struct mmc_host *host)
>>>>
>>>>                 explicit_inv_cd = of_property_read_bool(np, "cd-inverted");
>>>>
>>>> -               if (of_find_property(np, "broken-cd", &len))
>>>> -                       host->caps |= MMC_CAP_NEEDS_POLL;
>>>> -
>>>>                 gpio = of_get_named_gpio_flags(np, "cd-gpios", 0, &flags);
>>>>                 if (gpio == -EPROBE_DEFER)
>>>>                         return gpio;
>>>> --
>>>> 1.7.9.5
>>> --
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>>
>