Hi,
On 2017-02-22 11:11, Andrzej Hajda wrote:
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@xxxxxxxxxxx>
With this patch TM2 board boots fine on linux-next from 21st Feb 2017
and maxcpus=1 in kernel command line.
Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
---
v2:
- removed doubled conditional
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 bea6071..00e81e3 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++];
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
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