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mmc: sdhci: Fix read-only detection with JMicron 388 chip 

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 a new sdhci quirk
indicating to check 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>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Takashi Iwai 2011-04-21 20:26:38 +02:00 committed by Chris Ball
parent f06c9153f5
commit 82b0e23a29
3 changed files with 31 additions and 4 deletions
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5
drivers/mmc/host/sdhci-pci.c
View File

@ -327,6 +327,11 @@ static int jmicron_probe(struct sdhci_pci_chip *chip)
return ret;
}
/* quirk for unsable RO-detection on JM388 chips */
if (chip->pdev->device == PCI_DEVICE_ID_JMICRON_JMB388_SD ||
chip->pdev->device == PCI_DEVICE_ID_JMICRON_JMB388_ESD)
chip->quirks |= SDHCI_QUIRK_UNSTABLE_RO_DETECT;
return 0;
}

28
drivers/mmc/host/sdhci.c
View File

@ -1256,14 +1256,11 @@ out:
spin_unlock_irqrestore(&host->lock, flags);
}
static int sdhci_get_ro(struct mmc_host *mmc)
static int check_ro(struct sdhci_host *host)
{
struct sdhci_host *host;
unsigned long flags;
int is_readonly;
host = mmc_priv(mmc);
spin_lock_irqsave(&host->lock, flags);
if (host->flags & SDHCI_DEVICE_DEAD)
@ -1281,6 +1278,29 @@ static int sdhci_get_ro(struct mmc_host *mmc)
!is_readonly : is_readonly;
}
#define SAMPLE_COUNT 5
static int sdhci_get_ro(struct mmc_host *mmc)
{
struct sdhci_host *host;
int i, ro_count;
host = mmc_priv(mmc);
if (!(host->quirks & SDHCI_QUIRK_UNSTABLE_RO_DETECT))
return check_ro(host);
ro_count = 0;
for (i = 0; i < SAMPLE_COUNT; i++) {
if (check_ro(host)) {
if (++ro_count > SAMPLE_COUNT / 2)
return 1;
}
msleep(30);
}
return 0;
}
static void sdhci_enable_sdio_irq(struct mmc_host *mmc, int enable)
{
struct sdhci_host *host;

2
include/linux/mmc/sdhci.h
View File

@ -85,6 +85,8 @@ struct sdhci_host {
#define SDHCI_QUIRK_NO_HISPD_BIT (1<<29)
/* Controller treats ADMA descriptors with length 0000h incorrectly */
#define SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC (1<<30)
/* The read-only detection via SDHCI_PRESENT_STATE register is unstable */
#define SDHCI_QUIRK_UNSTABLE_RO_DETECT (1<<31)
int irq; /* Device IRQ */
void __iomem *ioaddr; /* Mapped address */