From d25928d1eed06a9c23c723466dfa7cbee0a5e07d Mon Sep 17 00:00:00 2001 From: Shawn Guo Date: Tue, 21 Jun 2011 22:41:48 +0800 Subject: mmc: sdhci: fix interrupt storm from card detection The issue was initially found by Eric Benard as below. http://permalink.gmane.org/gmane.linux.ports.arm.kernel/108031 Not sure about other SDHCI based controller, but on Freescale eSDHC, the SDHCI_INT_CARD_INSERT bits will be immediately set again when it gets cleared, if a card is inserted. The driver need to mask the irq to prevent interrupt storm which will freeze the system. And the SDHCI_INT_CARD_REMOVE gets the same situation. The patch fixes the problem based on the initial idea from Eric Benard. Signed-off-by: Shawn Guo Cc: Eric Benard Tested-by: Arnaud Patard Signed-off-by: Chris Ball --- drivers/mmc/host/sdhci.c | 29 +++++++++++++++++++++++++---- 1 file changed, 25 insertions(+), 4 deletions(-) (limited to 'drivers/mmc/host/sdhci.c') diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 58d5436ff649..aa25eae65402 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -127,11 +127,15 @@ static void sdhci_mask_irqs(struct sdhci_host *host, u32 irqs) static void sdhci_set_card_detection(struct sdhci_host *host, bool enable) { - u32 irqs = SDHCI_INT_CARD_REMOVE | SDHCI_INT_CARD_INSERT; + u32 present, irqs; if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) return; + present = sdhci_readl(host, SDHCI_PRESENT_STATE) & + SDHCI_CARD_PRESENT; + irqs = present ? SDHCI_INT_CARD_REMOVE : SDHCI_INT_CARD_INSERT; + if (enable) sdhci_unmask_irqs(host, irqs); else @@ -2154,13 +2158,30 @@ static irqreturn_t sdhci_irq(int irq, void *dev_id) mmc_hostname(host->mmc), intmask); if (intmask & (SDHCI_INT_CARD_INSERT | SDHCI_INT_CARD_REMOVE)) { + u32 present = sdhci_readl(host, SDHCI_PRESENT_STATE) & + SDHCI_CARD_PRESENT; + + /* + * There is a observation on i.mx esdhc. INSERT bit will be + * immediately set again when it gets cleared, if a card is + * inserted. We have to mask the irq to prevent interrupt + * storm which will freeze the system. And the REMOVE gets + * the same situation. + * + * More testing are needed here to ensure it works for other + * platforms though. + */ + sdhci_mask_irqs(host, present ? SDHCI_INT_CARD_INSERT : + SDHCI_INT_CARD_REMOVE); + sdhci_unmask_irqs(host, present ? SDHCI_INT_CARD_REMOVE : + SDHCI_INT_CARD_INSERT); + sdhci_writel(host, intmask & (SDHCI_INT_CARD_INSERT | - SDHCI_INT_CARD_REMOVE), SDHCI_INT_STATUS); + SDHCI_INT_CARD_REMOVE), SDHCI_INT_STATUS); + intmask &= ~(SDHCI_INT_CARD_INSERT | SDHCI_INT_CARD_REMOVE); tasklet_schedule(&host->card_tasklet); } - intmask &= ~(SDHCI_INT_CARD_INSERT | SDHCI_INT_CARD_REMOVE); - if (intmask & SDHCI_INT_CMD_MASK) { sdhci_writel(host, intmask & SDHCI_INT_CMD_MASK, SDHCI_INT_STATUS); -- cgit v1.2.3 From 58d1246db340793c408b22884598e4ce4d1d4aba Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Tue, 28 Jun 2011 17:16:03 +0300 Subject: mmc: sdhci: specify maximum discard timeout In general, SDHC hardware timeout cannot be avoided. Accordingly, the maximum timeout is specified to limit the maximum discard size. Signed-off-by: Adrian Hunter Signed-off-by: Chris Ball --- drivers/mmc/host/sdhci.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/mmc/host/sdhci.c') diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index aa25eae65402..c31a3343340d 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -2509,6 +2509,11 @@ int sdhci_add_host(struct sdhci_host *host) } else mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_200; + if (host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK) + mmc->max_discard_to = (1 << 27) / (mmc->f_max / 1000); + else + mmc->max_discard_to = (1 << 27) / host->timeout_clk; + mmc->caps |= MMC_CAP_SDIO_IRQ | MMC_CAP_ERASE | MMC_CAP_CMD23; if (host->quirks & SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12) -- cgit v1.2.3