From: Chris Brandt <chris.bra...@renesas.com>

commit a71e2ac1f32097fbb2beab098687a7a95c84543e upstream.

The NACKF flag should be cleared in INTRIICNAKI interrupt processing as
description in HW manual.

This issue shows up quickly when PREEMPT_RT is applied and a device is
probed that is not plugged in (like a touchscreen controller). The result
is endless interrupts that halt system boot.

Fixes: 310c18a41450 ("i2c: riic: add driver")
Cc: sta...@vger.kernel.org
Reported-by: Chien Nguyen <chien.nguyen...@rvc.renesas.com>
Signed-off-by: Chris Brandt <chris.bra...@renesas.com>
Signed-off-by: Wolfram Sang <w...@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/i2c/busses/i2c-riic.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/i2c/busses/i2c-riic.c
+++ b/drivers/i2c/busses/i2c-riic.c
@@ -202,6 +202,7 @@ static irqreturn_t riic_tend_isr(int irq
        if (readb(riic->base + RIIC_ICSR2) & ICSR2_NACKF) {
                /* We got a NACKIE */
                readb(riic->base + RIIC_ICDRR); /* dummy read */
+               riic_clear_set_bit(riic, ICSR2_NACKF, 0, RIIC_ICSR2);
                riic->err = -ENXIO;
        } else if (riic->bytes_left) {
                return IRQ_NONE;


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