On Jun 21, 2011, at 9:40 PM, Shawn Guo wrote: > 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. understand -- I'm happy with the results ! Philip > >>> + 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
