[v2] i2c: riic: Clear NACK in tend isr
diff mbox series

Message ID 20190926121909.1795-1-chris.brandt@renesas.com
State Accepted
Headers show
Series
  • [v2] i2c: riic: Clear NACK in tend isr
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Commit Message

Chris Brandt Sept. 26, 2019, 12:19 p.m. UTC
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>

---
v2:
 * Added Cc for stable
---
 drivers/i2c/busses/i2c-riic.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Wolfram Sang Sept. 28, 2019, 6:24 p.m. UTC | #1
On Thu, Sep 26, 2019 at 07:19:09AM -0500, Chris Brandt wrote:
> 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>
> 

Applied to for-current, thanks!

Patch
diff mbox series

diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c
index f31413fd9521..800414886f6b 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;