Re: Warnings for invalid VDD (sdhci-s3c)

[Jisheng Zhang]

On Thu, 24 Mar 2016 15:21:47 +0200
Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:

> On 24/03/16 15:11, Adrian Hunter wrote:
> > On 24/03/16 10:42, Krzysztof Kozlowski wrote:  
> >> On 24.03.2016 17:24, Jisheng Zhang wrote:  
> >>> Hi,
> >>>
> >>> On Thu, 24 Mar 2016 17:09:27 +0900 Jaehoon Chung wrote:
> >>>  
> >>>> Hi,
> >>>>
> >>>> On 03/24/2016 04:58 PM, Jisheng Zhang wrote:  
> >>>>> Hi,
> >>>>>
> >>>>> On Thu, 24 Mar 2016 16:28:56 +0900 Krzysztof Kozlowski wrote:
> >>>>>     
> >>>>>> Hi,
> >>>>>>
> >>>>>> After 918f4cbd4340 ("mmc: sdhci: restore behavior when setting VDD via
> >>>>>> external regulator") On Trats2 board I see warnings for invalid VDD
> >>>>>> value (2.8V):
> >>>>>>
> >>>>>> [    3.119656] ------------[ cut here ]------------
> >>>>>> [    3.119666] WARNING: CPU: 3 PID: 90 at
> >>>>>> ../drivers/mmc/host/sdhci.c:1234 sdhci_do_set_ios+0x4cc/0x5e0
> >>>>>> [    3.119669] mmc0: Invalid vdd 0x10    
> >>>>>
> >>>>> Per my understanding, the wrong vdd indicates a wrong ocr, what's the voltage of
> >>>>> this host's vmmc regulator?    
> >>>>
> >>>> As i know, it's fixed-voltage with gpio on trats2. It's 2.8V.
> >>>> I didn't check this entirely..need to check ocr value.
> >>>>  
> >>>
> >>> I may know the reason. the vmmc is 2.8v, then mmc_regulator_get_supply() convert
> >>> the value to a ocr as 0x10. The key here is that the 2.8v is invalid in SDHCI
> >>> case and isn't accepted by current sdhci driver.  
> >>
> >> Yeah, I already wrote that. It is the part of the warning and my email.
> >> Our regulator is fixed at 2.8 which is 0x10. :)
> >>  
> >>> I dunno the elegant solution to handle this case, let's wait for sdhci maintainers
> >>> idea.  
> >>
> >> Hmm...  
> > 
> > I haven't tested it, but what about this:  
> 
> And now with checkpatch complaints fixed:
> 
> From: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Date: Thu, 24 Mar 2016 14:29:24 +0200
> Subject: [PATCH V2] mmc: sdhci: Fix regression setting power on Trats2 board
> 
> Several commits relating to setting power have been introducing
> problems by putting driver-specific rules into generic SDHCI code.
> 
> Fix by adding a 'set_power' callback and restoring the default
> behaviour prior to commit 918f4cbd4340 ("mmc: sdhci: restore
> behavior when setting VDD via external regulator").  The desired
> behaviour of that commit is gotten by having sdhci-pxav3 provide
> its own set_power callback.
> 
> Reported-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
> Fixes: 918f4cbd4340 ("mmc: sdhci: restore behavior when setting VDD...)
> Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>

Reviewed-by: Jisheng Zhang <jszhang@xxxxxxxxxxx>
Tested-by: Jisheng Zhang <jszhang@xxxxxxxxxxx>

The only problem is atmel's sdhc host also need similar own .set_power
Ludovic knows details.

Thanks,
Jisheng

> Cc: stable@xxxxxxxxxxxxxxx # v4.5+
> ---
>  drivers/mmc/host/sdhci-pxav3.c | 17 +++++++++++++++++
>  drivers/mmc/host/sdhci.c       | 38 ++++++++++++++++++++++++++++++--------
>  drivers/mmc/host/sdhci.h       |  4 ++++
>  3 files changed, 51 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-pxav3.c b/drivers/mmc/host/sdhci-pxav3.c
> index f5edf9d3a18a..673d1e8446a5 100644
> --- a/drivers/mmc/host/sdhci-pxav3.c
> +++ b/drivers/mmc/host/sdhci-pxav3.c
> @@ -307,8 +307,25 @@ static void pxav3_set_uhs_signaling(struct sdhci_host *host, unsigned int uhs)
>  		__func__, uhs, ctrl_2);
>  }
>  
> +static void pxav3_set_power(struct sdhci_host *host, unsigned char mode,
> +			    unsigned short vdd)
> +{
> +	struct mmc_host *mmc = host->mmc;
> +	u8 pwr = host->pwr;
> +
> +	sdhci_set_power(host, mode, vdd);
> +
> +	if (host->pwr == pwr)
> +		return;
> +
> +	spin_unlock_irq(&host->lock);
> +	mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
> +	spin_lock_irq(&host->lock);
> +}
> +
>  static const struct sdhci_ops pxav3_sdhci_ops = {
>  	.set_clock = sdhci_set_clock,
> +	.set_power = pxav3_set_power,
>  	.platform_send_init_74_clocks = pxav3_gen_init_74_clocks,
>  	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
>  	.set_bus_width = sdhci_set_bus_width,
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index add9fdfd1d8f..282257222121 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1269,10 +1269,24 @@ clock_set:
>  }
>  EXPORT_SYMBOL_GPL(sdhci_set_clock);
>  
> -static void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
> -			    unsigned short vdd)
> +static void sdhci_set_power_reg(struct sdhci_host *host, unsigned char mode,
> +				unsigned short vdd)
>  {
>  	struct mmc_host *mmc = host->mmc;
> +
> +	spin_unlock_irq(&host->lock);
> +	mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
> +	spin_lock_irq(&host->lock);
> +
> +	if (mode != MMC_POWER_OFF)
> +		sdhci_writeb(host, SDHCI_POWER_ON, SDHCI_POWER_CONTROL);
> +	else
> +		sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
> +}
> +
> +void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
> +		     unsigned short vdd)
> +{
>  	u8 pwr = 0;
>  
>  	if (mode != MMC_POWER_OFF) {
> @@ -1335,12 +1349,20 @@ static void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
>  		if (host->quirks & SDHCI_QUIRK_DELAY_AFTER_POWER)
>  			mdelay(10);
>  	}
> +}
> +EXPORT_SYMBOL_GPL(sdhci_set_power);
>  
> -	if (!IS_ERR(mmc->supply.vmmc)) {
> -		spin_unlock_irq(&host->lock);
> -		mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd);
> -		spin_lock_irq(&host->lock);
> -	}
> +static void __sdhci_set_power(struct sdhci_host *host, unsigned char mode,
> +			      unsigned short vdd)
> +{
> +	struct mmc_host *mmc = host->mmc;
> +
> +	if (host->ops->set_power)
> +		host->ops->set_power(host, mode, vdd);
> +	else if (!IS_ERR(mmc->supply.vmmc))
> +		sdhci_set_power_reg(host, mode, vdd);
> +	else
> +		sdhci_set_power(host, mode, vdd);
>  }
>  
>  /*****************************************************************************\
> @@ -1490,7 +1512,7 @@ static void sdhci_do_set_ios(struct sdhci_host *host, struct mmc_ios *ios)
>  		}
>  	}
>  
> -	sdhci_set_power(host, ios->power_mode, ios->vdd);
> +	__sdhci_set_power(host, ios->power_mode, ios->vdd);
>  
>  	if (host->ops->platform_send_init_74_clocks)
>  		host->ops->platform_send_init_74_clocks(host, ios->power_mode);
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 0115e9907bf8..033d72b5bbd5 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -529,6 +529,8 @@ struct sdhci_ops {
>  #endif
>  
>  	void	(*set_clock)(struct sdhci_host *host, unsigned int clock);
> +	void	(*set_power)(struct sdhci_host *host, unsigned char mode,
> +			     unsigned short vdd);
>  
>  	int		(*enable_dma)(struct sdhci_host *host);
>  	unsigned int	(*get_max_clock)(struct sdhci_host *host);
> @@ -660,6 +662,8 @@ static inline bool sdhci_sdio_irq_enabled(struct sdhci_host *host)
>  }
>  
>  void sdhci_set_clock(struct sdhci_host *host, unsigned int clock);
> +void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
> +		     unsigned short vdd);
>  void sdhci_set_bus_width(struct sdhci_host *host, int width);
>  void sdhci_reset(struct sdhci_host *host, u8 mask);
>  void sdhci_set_uhs_signaling(struct sdhci_host *host, unsigned timing);