diff mbox

i2c: exynos5: disable fifo-almost-empty irq signal when necessary

Message ID 1487754465-10190-1-git-send-email-a.hajda@samsung.com (mailing list archive)
State Not Applicable
Headers show

Commit Message

Andrzej Hajda Feb. 22, 2017, 9:07 a.m. UTC 
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 <a.hajda@samsung.com>
---
 drivers/i2c/busses/i2c-exynos5.c | 6 ++++++
 1 file changed, 6 insertions(+)
diff mbox

Patch

diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
index bea6071..2e11793 100644
--- a/drivers/i2c/busses/i2c-exynos5.c
+++ b/drivers/i2c/busses/i2c-exynos5.c
@@ -503,7 +503,13 @@  static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id)
 
 		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++];