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@xxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
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
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