Re: [PATCH] Revert "mmc: dw_mmc-rockchip: add runtime PM support"

[Jaehoon Chung]

Hi John,

On 01/23/2017 08:24 PM, John Keeping wrote:
> Hi,
> 
> On Fri, 20 Jan 2017 15:08:57 +0900, Jaehoon Chung wrote:
>> On 01/17/2017 10:38 PM, Romain Perier wrote:
>>> In my case I can reproduce the issue on the rock2 and the firefly-rk3288. A workaround is to
>>>
>>> comment the line ".pm = <&pm_ops_foo>" .  
>>
>> Sorry for late. I'm checking runtime PM for this. 
>> After that, i will decide whether revert or not.
> 
> I hit this problem on Rock2 when trying 4.10-rc4.  The following patch
> fixes it for me.

Could you check with Ulf's repository?

https://git.kernel.org/cgit/linux/kernel/git/ulfh/mmc.git/commit/?h=next&id=e86738ac78c22956f1c787ebafefc83d43cab30a

Shawn's patch was applied. If also occurred the same issue, let me know, plz.

> 
> I'm not sure if this is safe in general or whether it should be guarded
> by a quirk that is enabled for RK3288.
> 
> -- >8 --
> Subject: [PATCH] mmc: dw_mmc: restore CIU state on resume
> 
> At least on RK3288, asserting SDMMC_CTRL_RESET causes the CIU to reset
> and disable the clock.  We need to send SDMMC_CMD_UPD_CLK after doing
> this in order to avoid the MMC host hanging.
> 
> Signed-off-by: John Keeping <john@xxxxxxxxxxxx>
> ---
>  drivers/mmc/host/dw_mmc.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index b44306b886cb..e7504dabcfb6 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -3311,6 +3311,7 @@ int dw_mci_runtime_resume(struct device *dev)
>  {
>  	int i, ret = 0;
>  	struct dw_mci *host = dev_get_drvdata(dev);
> +	u32 sdmmc_cmd_bits = SDMMC_CMD_UPD_CLK | SDMMC_CMD_PRV_DAT_WAIT;
>  
>  	if (host->cur_slot &&
>  	    (mmc_can_gpio_cd(host->cur_slot->mmc) ||
> @@ -3357,6 +3358,9 @@ int dw_mci_runtime_resume(struct device *dev)
>  		if (slot->mmc->pm_flags & MMC_PM_KEEP_POWER) {
>  			dw_mci_set_ios(slot->mmc, &slot->mmc->ios);
>  			dw_mci_setup_bus(slot, true);
> +		} else {
> +			/* restore CIU */
> +			mci_send_cmd(slot, sdmmc_cmd_bits, 0);
>  		}
>  	}
>  
>