On Tue, Jun 21, 2011 at 09:05:25AM -0700, Philip Rakity wrote: > > 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 > I actually rewrote the body of the if-statement, and fixed one indentation in that specific line. > > + 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> > -- Regards, Shawn -- 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
