On 2017/1/9 13:41, Jaehoon Chung wrote:
> On 01/09/2017 12:39 PM, Ziyuan wrote:
>>
>>
>> On 01/05/2017 03:34 PM, Shawn Lin wrote:
>>> On 2017/1/5 15:23, Ziyuan Xu wrote:
>>>> It's necessary to setup bus if any slots are present.
>>>> - update clock after ctrl reset
>>>> - if the host has genpd node, we can guarantee the clock is available
>>>> before starting request. Otherwies, the clock register is reset once
>>>> power off the pd, and host can't output the active clock during
>>>> communication.
>>>>
>>>> fixes: e9ed8835e990 ("mmc: dw_mmc: add runtime PM callback")
>>>> Reported-by: Randy Li <randy.li at rock-chips.com>
>>>> Signed-off-by: Ziyuan Xu <xzy.xu at rock-chips.com>
>>>>
>>>> ---
>>>> Hi guys,
>>>>
>>>> I found a similar issue on rk3399 platform, which has a genpd node for
>>>> SD card host. Power off-on pd will reset the registers to a default
>>>> value (ie. CLKENA), so that the host can't output the active clock
>>>> during communication.
>>>>
>>>
>>> Indeed, Caesar recently introduced all the genpd for rk3399 platform,
>>> so we need to restore them.
>>>
>>>> So we need to setup bus in rpm resume. It also wraps the update clock
>>>> behaviour which I did in V3.
>>>>
>>>> Thanks,
>>>> Ziyuan Xu
>>>>
>>>>
>>>> Changes in v4:
>>>> - update commit message
>>>> - fix SD host rpm resume can't work
>>>>
>>>> Changes in v3:
>>>> - only reset host with active slot.
>>>>
>>>> Changes in v2:
>>>> - update the commit message
>>>> - use dw_mci_reset instead of dw_mci_ctrl_reset
>>>>
>>>> drivers/mmc/host/dw_mmc.c | 6 +++---
>>>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>>>> index b44306b..b6053b3 100644
>>>> --- a/drivers/mmc/host/dw_mmc.c
>>>> +++ b/drivers/mmc/host/dw_mmc.c
>>>> @@ -3354,10 +3354,10 @@ int dw_mci_runtime_resume(struct device *dev)
>>>>
>>>> if (!slot)
>>>> continue;
>>>> - if (slot->mmc->pm_flags & MMC_PM_KEEP_POWER) {
>>>> + if (slot->mmc->pm_flags & MMC_PM_KEEP_POWER)
>>>> dw_mci_set_ios(slot->mmc, &slot->mmc->ios);
>>>> - dw_mci_setup_bus(slot, true);
>>>> - }
>>>> + /* Force setup bus to guarantee available clock output */
>>>> + dw_mci_setup_bus(slot, true);
>>>
>>> So the spamming message about
>>>
>>> "Bus speed (slot %d) = %dHz (slot req %dHz, actual %dHZ div = %d)\n"
>>>
>>> will always be there, right? So you could append a new patch to shut
>>> up it as I think it's useless no matter for system pm or rpm to print
>>> it. How about?
>>
>> Fine, it's favourable with dev_vdbg if the dw_mmc rpm is enabled.
>> Hi Jaehoon,
>> What's your opinion? If you think this patch and shawn's advice are acceptable, I will send the v5 patch.
>
> I don't agreed to use dev_vdbg()..but it needs not to display at everytime.
> Hmm..It needs to consider more..because we needs to see the clock value when it's initialized.
>
A very stright-forward way is to pass a flag to shut up the spamming
log when it's called from the PM context?
> Best Regards,
> Jaehoon Chung
>
>>
>> BR
>> Ziyuan Xu
>>
>>>
>>>> }
>>>>
>>>> /* Now that slots are all setup, we can enable card detect */
>>>>
>>>
>>>
>>
>>
>>
>>
>>
>
>
>
>
--
Best Regards
Shawn Lin
