Hi Bing, Chris,

On Tue, 2010-09-07 at 19:10 -0700, Bing Zhao wrote:
> Hi Nicolas,
> 
> > -----Original Message-----
> > From: Nicolas Pitre [mailto:[email protected]]
> > Sent: Tuesday, September 07, 2010 6:29 PM
> > To: Bing Zhao
> > Cc: [email protected]; Michal Miroslaw; Chris Ball; Andrew Morton
> > Subject: RE: [PATCH v2] sdio: skip initialization on powered resume
> > 
> > On Tue, 7 Sep 2010, Bing Zhao wrote:
> > 
> > > Thanks for the hint.
> > >
> > > The new patch skips reading CCCR, common CIS, and validation of
> > > vendor/device IDs inside mmc_sdio_init_card() when powered_resume is
> > > not zero.
> > 
> > Why do you skip the reading of the CIS and IDs validation?  That's
> > basically the main reason for still calling mmc_sdio_init_card().  And
> > that only requires CMD 52 so that should be fine.
> 
> While the system is suspended, the SDIO card could be in sleep mode (deep 
> sleep or IEEE Power Save) as well. Reading CIS or any other CMD52 will fail 
> if the card happens to be in sleep at this moment. If we skip 
> re-initialization (including CCCR/CIS and IDs validation), 
> mmc_sdio_init_card() returns success. Then the client driver's resume() 
> handler will be called and the card can be woken up by client driver.

In one of your previous patches, "sdio: don't use CMD[357] as part of a
powered SDIO resume", its mentioned that there is an issue with CMD7 in
mmc_sdio_init_card() that is called during SDIO resume on Marvell 8686.

But in mmc_resume_host(), there is still a call to mmc_detect_change()
which in turn calls mmc_sdio_detect(), thus sending CMD7 to the card.
Does CMD7 to your card succeed after your client driver resume is
called?

Thanks,
Sahitya.

--
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
Forum.


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