Commit 82b0e23a authored by Takashi Iwai's avatar Takashi Iwai Committed by Chris Ball
Browse files

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: default avatarTakashi Iwai <tiwai@suse.de>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent f06c9153

drivers/mmc/host/sdhci-pci.c

+5 −0
Original line number Diff line number Diff line
@@ -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;

}

drivers/mmc/host/sdhci.c

+24 −4
Original line number Diff line number Diff line
@@ -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;

include/linux/mmc/sdhci.h

+2 −0
Original line number Diff line number Diff line
@@ -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 */

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