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Commit 68d1fb7e authored by Anton Vorontsov's avatar Anton Vorontsov Committed by Pierre Ossman
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sdhci: Add support for card-detection polling 



This patch adds SDHCI_QUIRK_BROKEN_CARD_DETECTION quirk. When specified,
sdhci driver will set MMC_CAP_NEEDS_POLL MMC host capability, and won't
enable card insert/remove interrupts.

This is needed for hosts with unreliable card detection, such as FSL
eSDHC. The original eSDHC driver was tring to "debounce" card-detection
IRQs by reading present state and disabling particular interrupts. But
with this debouncing scheme I noticed that sometimes we miss card
insertion/removal events.

Signed-off-by: default avatarAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: default avatarPierre Ossman <drzeus@drzeus.cx>
parent 6aa943ab

drivers/mmc/host/sdhci.c

+15 −2
Original line number Diff line number Diff line
@@ -112,6 +112,9 @@ static void sdhci_set_card_detection(struct sdhci_host *host, bool enable) 
{

	u32 irqs = SDHCI_INT_CARD_REMOVE | SDHCI_INT_CARD_INSERT;



	if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION)

		return;



	if (enable)

		sdhci_unmask_irqs(host, irqs);

	else
@@ -1041,6 +1044,7 @@ out: 
static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)

{

	struct sdhci_host *host;

	bool present;

	unsigned long flags;



	host = mmc_priv(mmc);
@@ -1055,8 +1059,14 @@ static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq) 


	host->mrq = mrq;



	if (!(sdhci_readl(host, SDHCI_PRESENT_STATE) & SDHCI_CARD_PRESENT)

		|| (host->flags & SDHCI_DEVICE_DEAD)) {

	/* If polling, assume that the card is always present. */

	if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION)

		present = true;

	else

		present = sdhci_readl(host, SDHCI_PRESENT_STATE) &

				SDHCI_CARD_PRESENT;



	if (!present || host->flags & SDHCI_DEVICE_DEAD) {

		host->mrq->cmd->error = -ENOMEDIUM;

		tasklet_schedule(&host->finish_tasklet);

	} else
@@ -1690,6 +1700,9 @@ int sdhci_add_host(struct sdhci_host *host) 
	if (caps & SDHCI_CAN_DO_HISPD)

		mmc->caps |= MMC_CAP_SD_HIGHSPEED;



	if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION)

		mmc->caps |= MMC_CAP_NEEDS_POLL;



	mmc->ocr_avail = 0;

	if (caps & SDHCI_CAN_VDD_330)

		mmc->ocr_avail |= MMC_VDD_32_33|MMC_VDD_33_34;

drivers/mmc/host/sdhci.h

+2 −0
Original line number Diff line number Diff line
@@ -214,6 +214,8 @@ struct sdhci_host { 
#define SDHCI_QUIRK_BROKEN_SMALL_PIO			(1<<13)

/* Controller does not provide transfer-complete interrupt when not busy */

#define SDHCI_QUIRK_NO_BUSY_IRQ				(1<<14)

/* Controller has unreliable card detection */

#define SDHCI_QUIRK_BROKEN_CARD_DETECTION		(1<<15)



	int			irq;		/* Device IRQ */

	void __iomem *		ioaddr;		/* Mapped address */