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>
diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c
index 82c5dc4..936bbca 100644
--- a/drivers/mmc/host/sdhci-pci.c
+++ b/drivers/mmc/host/sdhci-pci.c
@@ -327,6 +327,11 @@
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;
}
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index a70a3d1..e5cfe70 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1256,14 +1256,11 @@
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 @@
!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;