From fd1c9c8568439198a66f42108a9b01854e25346e Mon Sep 17 00:00:00 2001 From: Andrzej Hajda Date: Wed, 22 Feb 2017 11:11:20 +0100 Subject: [PATCH] i2c: exynos5: disable fifo-almost-empty irq signal when necessary Fifo-almost-empty irq signal should be disabled as soon as possible, to avoid unnecessary interrupt storm. The best moment is when there is no more data to feed fifo. This patch fixes system stalls caused by IRQ storm. Signed-off-by: Andrzej Hajda Tested-by: Marek Szyprowski Tested-by: Andi Shyti Reviewed-by: Andi Shyti Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-exynos5.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c index bea607149972..00e81e3564ff 100644 --- a/drivers/i2c/busses/i2c-exynos5.c +++ b/drivers/i2c/busses/i2c-exynos5.c @@ -502,8 +502,13 @@ static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id) fifo_level = HSI2C_TX_FIFO_LVL(fifo_status); len = i2c->variant->fifo_depth - fifo_level; - if (len > (i2c->msg->len - i2c->msg_ptr)) + if (len > (i2c->msg->len - i2c->msg_ptr)) { + u32 int_en = readl(i2c->regs + HSI2C_INT_ENABLE); + + int_en &= ~HSI2C_INT_TX_ALMOSTEMPTY_EN; + writel(int_en, i2c->regs + HSI2C_INT_ENABLE); len = i2c->msg->len - i2c->msg_ptr; + } while (len > 0) { byte = i2c->msg->buf[i2c->msg_ptr++]; -- 2.20.1