From 75aaa6f61279758196e5a82b77288109a6a0b5a2 Mon Sep 17 00:00:00 2001 From: Chris Brandt Date: Thu, 26 Sep 2019 07:19:09 -0500 Subject: [PATCH] i2c: riic: Clear NACK in tend isr 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: stable@vger.kernel.org Reported-by: Chien Nguyen Signed-off-by: Chris Brandt Signed-off-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman --- drivers/i2c/busses/i2c-riic.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c index c811af4..e420b41 100644 --- a/drivers/i2c/busses/i2c-riic.c +++ b/drivers/i2c/busses/i2c-riic.c @@ -212,6 +212,7 @@ static irqreturn_t riic_tend_isr(int irq, void *data) 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; -- 2.7.4