[PATCH] mmc: Fix read-only detection with JMicron 388 chip

[PATCH] mmc: Fix read-only detection with JMicron 388 chip

[Takashi Iwai]

On HP laptops with JMicron 388 chip, the write-locked SD card isn't
detected correctly as read-only in many cases.  This is because the
PRESENT_STATE register becomes unsable just after plugging, and it
returns the WRITE_PROTECT bit wrongly at the first read.

This patch fixes the read-only detection by adding the own get_ro op
for checking the register more intensively with a relatively long
delay.

The patch is tested with 2.6.39-rc4 kernel.

Cc: Aries Lee <arieslee@jmicron.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 drivers/mmc/host/sdhci-pci.c |   34 ++++++++++++++++++++++++++++++++++
 1 files changed, 34 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c
index a136be7..9037b2a 100644
--- a/drivers/mmc/host/sdhci-pci.c
+++ b/drivers/mmc/host/sdhci-pci.c
@@ -346,6 +346,35 @@ static void jmicron_enable_mmc(struct sdhci_host *host, int on)
 	writeb(scratch, host->ioaddr + 0xC0);
 }
 
+/* As PRESENT_STATE register becomes unstable just after plugging,
+ * need to check the RO-cap multiple times with a relatively long delay.
+ */
+
+#define SAMPLE_COUNT	5
+
+static unsigned int jmicron_get_ro(struct sdhci_host *host)
+{
+	int i, ro_count;
+
+	ro_count = 0;
+	for (i = 0; i < SAMPLE_COUNT; i++) {
+		int present = sdhci_readl(host, SDHCI_PRESENT_STATE);
+		if (!(present & SDHCI_WRITE_PROTECT)) {
+			if (++ro_count > SAMPLE_COUNT / 2)
+				return 1;
+		}
+		msleep(30);
+	}
+	return 0;
+}
+
+static int sdhci_pci_enable_dma(struct sdhci_host *host);
+
+static struct sdhci_ops jmicron_pci_ops = {
+	.enable_dma	= sdhci_pci_enable_dma,
+	.get_ro		= jmicron_get_ro,
+};
+
 static int jmicron_probe_slot(struct sdhci_pci_slot *slot)
 {
 	if (slot->chip->pdev->revision == 0) {
@@ -383,6 +412,11 @@ static int jmicron_probe_slot(struct sdhci_pci_slot *slot)
 
 	slot->host->mmc->caps |= MMC_CAP_BUS_WIDTH_TEST;
 
+	/* Replace the ops for unstable get_ro detection */
+	if (slot->chip->pdev->device == PCI_DEVICE_ID_JMICRON_JMB388_SD ||
+	    slot->chip->pdev->device == PCI_DEVICE_ID_JMICRON_JMB388_ESD)
+		slot->host->ops = &jmicron_pci_ops;
+
 	return 0;
 }
 
-- 
1.7.4.2

Re: [PATCH] mmc: Fix read-only detection with JMicron 388 chip

[Chris Ball]

Hi Takashi,

On Thu, Apr 21 2011, Takashi Iwai wrote:
> On HP laptops with JMicron 388 chip, the write-locked SD card isn't
> detected correctly as read-only in many cases.  This is because the
> PRESENT_STATE register becomes unsable just after plugging, and it
> returns the WRITE_PROTECT bit wrongly at the first read.
>
> This patch fixes the read-only detection by adding the own get_ro op
> for checking the register more intensively with a relatively long
> delay.
>
> The patch is tested with 2.6.39-rc4 kernel.
>
> Cc: Aries Lee <arieslee@jmicron.com>
> Signed-off-by: Takashi Iwai <tiwai@suse.de>
> ---
>  drivers/mmc/host/sdhci-pci.c |   34 ++++++++++++++++++++++++++++++++++
>  1 files changed, 34 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c
> index a136be7..9037b2a 100644
> --- a/drivers/mmc/host/sdhci-pci.c
> +++ b/drivers/mmc/host/sdhci-pci.c
> @@ -346,6 +346,35 @@ static void jmicron_enable_mmc(struct sdhci_host *host, int on)
>  	writeb(scratch, host->ioaddr + 0xC0);
>  }
>  
> +/* As PRESENT_STATE register becomes unstable just after plugging,
> + * need to check the RO-cap multiple times with a relatively long delay.
> + */
> +
> +#define SAMPLE_COUNT	5
> +
> +static unsigned int jmicron_get_ro(struct sdhci_host *host)
> +{
> +	int i, ro_count;
> +
> +	ro_count = 0;
> +	for (i = 0; i < SAMPLE_COUNT; i++) {
> +		int present = sdhci_readl(host, SDHCI_PRESENT_STATE);
> +		if (!(present & SDHCI_WRITE_PROTECT)) {
> +			if (++ro_count > SAMPLE_COUNT / 2)
> +				return 1;
> +		}
> +		msleep(30);
> +	}
> +	return 0;
> +}
> +
> +static int sdhci_pci_enable_dma(struct sdhci_host *host);
> +
> +static struct sdhci_ops jmicron_pci_ops = {
> +	.enable_dma	= sdhci_pci_enable_dma,
> +	.get_ro		= jmicron_get_ro,
> +};
> +
>  static int jmicron_probe_slot(struct sdhci_pci_slot *slot)
>  {
>  	if (slot->chip->pdev->revision == 0) {
> @@ -383,6 +412,11 @@ static int jmicron_probe_slot(struct sdhci_pci_slot *slot)
>  
>  	slot->host->mmc->caps |= MMC_CAP_BUS_WIDTH_TEST;
>  
> +	/* Replace the ops for unstable get_ro detection */
> +	if (slot->chip->pdev->device == PCI_DEVICE_ID_JMICRON_JMB388_SD ||
> +	    slot->chip->pdev->device == PCI_DEVICE_ID_JMICRON_JMB388_ESD)
> +		slot->host->ops = &jmicron_pci_ops;
> +
>  	return 0;
>  }

I don't like overwriting ops here -- it's too magical, and now we have
to maintain the ops table in two places.  A quirk seems justified here,
even though we're trying to reduce them in general.  Can anyone find a
better solution?

Thanks,

- Chris.
-- 
Chris Ball   <cjb@laptop.org>   <http://printf.net/>
One Laptop Per Child

Re: [PATCH] mmc: Fix read-only detection with JMicron 388 chip

[Takashi Iwai]

At Thu, 21 Apr 2011 12:40:26 -0400,
Chris Ball wrote:
> 
> Hi Takashi,
> 
> On Thu, Apr 21 2011, Takashi Iwai wrote:
> > On HP laptops with JMicron 388 chip, the write-locked SD card isn't
> > detected correctly as read-only in many cases.  This is because the
> > PRESENT_STATE register becomes unsable just after plugging, and it
> > returns the WRITE_PROTECT bit wrongly at the first read.
> >
> > This patch fixes the read-only detection by adding the own get_ro op
> > for checking the register more intensively with a relatively long
> > delay.
> >
> > The patch is tested with 2.6.39-rc4 kernel.
> >
> > Cc: Aries Lee <arieslee@jmicron.com>
> > Signed-off-by: Takashi Iwai <tiwai@suse.de>
> > ---
> >  drivers/mmc/host/sdhci-pci.c |   34 ++++++++++++++++++++++++++++++++++
> >  1 files changed, 34 insertions(+), 0 deletions(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c
> > index a136be7..9037b2a 100644
> > --- a/drivers/mmc/host/sdhci-pci.c
> > +++ b/drivers/mmc/host/sdhci-pci.c
> > @@ -346,6 +346,35 @@ static void jmicron_enable_mmc(struct sdhci_host *host, int on)
> >  	writeb(scratch, host->ioaddr + 0xC0);
> >  }
> >  
> > +/* As PRESENT_STATE register becomes unstable just after plugging,
> > + * need to check the RO-cap multiple times with a relatively long delay.
> > + */
> > +
> > +#define SAMPLE_COUNT	5
> > +
> > +static unsigned int jmicron_get_ro(struct sdhci_host *host)
> > +{
> > +	int i, ro_count;
> > +
> > +	ro_count = 0;
> > +	for (i = 0; i < SAMPLE_COUNT; i++) {
> > +		int present = sdhci_readl(host, SDHCI_PRESENT_STATE);
> > +		if (!(present & SDHCI_WRITE_PROTECT)) {
> > +			if (++ro_count > SAMPLE_COUNT / 2)
> > +				return 1;
> > +		}
> > +		msleep(30);
> > +	}
> > +	return 0;
> > +}
> > +
> > +static int sdhci_pci_enable_dma(struct sdhci_host *host);
> > +
> > +static struct sdhci_ops jmicron_pci_ops = {
> > +	.enable_dma	= sdhci_pci_enable_dma,
> > +	.get_ro		= jmicron_get_ro,
> > +};
> > +
> >  static int jmicron_probe_slot(struct sdhci_pci_slot *slot)
> >  {
> >  	if (slot->chip->pdev->revision == 0) {
> > @@ -383,6 +412,11 @@ static int jmicron_probe_slot(struct sdhci_pci_slot *slot)
> >  
> >  	slot->host->mmc->caps |= MMC_CAP_BUS_WIDTH_TEST;
> >  
> > +	/* Replace the ops for unstable get_ro detection */
> > +	if (slot->chip->pdev->device == PCI_DEVICE_ID_JMICRON_JMB388_SD ||
> > +	    slot->chip->pdev->device == PCI_DEVICE_ID_JMICRON_JMB388_ESD)
> > +		slot->host->ops = &jmicron_pci_ops;
> > +
> >  	return 0;
> >  }
> 
> I don't like overwriting ops here -- it's too magical, and now we have
> to maintain the ops table in two places.  A quirk seems justified here,
> even though we're trying to reduce them in general.

Well, I also used quirk bit in my very first version I worked for
2.6.32 kernel.  But when I looked at 2.6.39, quirks are almost full --
only the last one bit is left for bit 31.  So I didn't want to finish
it :)

>  Can anyone find a better solution?
 
One way would be to copy the ops table itself in struct sdhci_host
instead of keeping the ops table pointer.  Then you can overwrite only
the specific op in each probe_slot callback.


thanks,

Takashi

Re: [PATCH] mmc: Fix read-only detection with JMicron 388 chip

[Chris Ball]

Hi Takashi,

On Thu, Apr 21 2011, Takashi Iwai wrote:
>> I don't like overwriting ops here -- it's too magical, and now we have
>> to maintain the ops table in two places.  A quirk seems justified here,
>> even though we're trying to reduce them in general.
>
> Well, I also used quirk bit in my very first version I worked for
> 2.6.32 kernel.  But when I looked at 2.6.39, quirks are almost full --
> only the last one bit is left for bit 31.  So I didn't want to finish
> it :)
>
>>  Can anyone find a better solution?
>  
> One way would be to copy the ops table itself in struct sdhci_host
> instead of keeping the ops table pointer.  Then you can overwrite only
> the specific op in each probe_slot callback.

I think I'd rather not touch ops at all and keep the code simple --
if you don't mind, please post a version with quirks, and I'll work
on freeing up a few bits.

Thanks,

- Chris.
-- 
Chris Ball   <cjb@laptop.org>   <http://printf.net/>
One Laptop Per Child

Re: [PATCH] mmc: Fix read-only detection with JMicron 388 chip

[Takashi Iwai]

At Thu, 21 Apr 2011 13:36:03 -0400,
Chris Ball wrote:
> 
> Hi Takashi,
> 
> On Thu, Apr 21 2011, Takashi Iwai wrote:
> >> I don't like overwriting ops here -- it's too magical, and now we have
> >> to maintain the ops table in two places.  A quirk seems justified here,
> >> even though we're trying to reduce them in general.
> >
> > Well, I also used quirk bit in my very first version I worked for
> > 2.6.32 kernel.  But when I looked at 2.6.39, quirks are almost full --
> > only the last one bit is left for bit 31.  So I didn't want to finish
> > it :)
> >
> >>  Can anyone find a better solution?
> >  
> > One way would be to copy the ops table itself in struct sdhci_host
> > instead of keeping the ops table pointer.  Then you can overwrite only
> > the specific op in each probe_slot callback.
> 
> I think I'd rather not touch ops at all and keep the code simple --
> if you don't mind, please post a version with quirks, and I'll work
> on freeing up a few bits.

OK, I'll send shortly.


Takashi