On Jun 21, 2011, at 7:41 AM, Shawn Guo wrote: > 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 <shawn.guo@xxxxxxxxxx> > Cc: Eric Benard <eric@xxxxxxxxxx> > Tested-by: Arnaud Patard <arnaud.patard@xxxxxxxxxxx> > --- > drivers/mmc/host/sdhci.c | 29 +++++++++++++++++++++++++---- > 1 files changed, 25 insertions(+), 4 deletions(-) > > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c > index 91d9892..790f959 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); ==== Please keep the old formatting since code does not change anything. Makes it easier to find the real change > + 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); > -- > 1.7.4.1 > Reviewed-by: Philip Rakity <prakity@xxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
