From: Chris Brandt chris.brandt@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: stable@vger.kernel.org Reported-by: Chien Nguyen chien.nguyen.eb@rvc.renesas.com Signed-off-by: Chris Brandt chris.brandt@renesas.com Signed-off-by: Wolfram Sang wsa@the-dreams.de Signed-off-by: Greg Kroah-Hartman gregkh@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 @@ -212,6 +212,7 @@ 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;