From cb506c56de88f3a61dff29e9915034cb4bfe72c9 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 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: e9c2059d2259 ("i2c: riic: add driver") Cc: stable@vger.kernel.org Reported-by: Chien Nguyen Signed-off-by: Chris Brandt Signed-off-by: Wolfram Sang --- 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 f31413fd9521e..800414886f6b5 100644 --- 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, 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; -- 2.39.5