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

[John Keeping]

On Mon, 23 Jan 2017 21:53:02 +0900, Jaehoon Chung wrote:

> 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 missed that patch, it also fixes the issue for me.

> > 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);
> >  		}
> >  	}
> >  
> >   
>