* [PATCH] i2c: riic: Clear NACK in tend isr
@ 2019-09-25 19:43 Chris Brandt
2019-09-26 4:54 ` Greg KH
0 siblings, 1 reply; 2+ messages in thread
From: Chris Brandt @ 2019-09-25 19:43 UTC (permalink / raw)
To: Wolfram Sang
Cc: stable, linux-i2c, linux-renesas-soc, Chris Brandt, Chien Nguyen
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")
Reported-by: Chien Nguyen <chien.nguyen.eb@rvc.renesas.com>
Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
---
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 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;
--
2.23.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] i2c: riic: Clear NACK in tend isr
2019-09-25 19:43 [PATCH] i2c: riic: Clear NACK in tend isr Chris Brandt
@ 2019-09-26 4:54 ` Greg KH
0 siblings, 0 replies; 2+ messages in thread
From: Greg KH @ 2019-09-26 4:54 UTC (permalink / raw)
To: Chris Brandt
Cc: Wolfram Sang, stable, linux-i2c, linux-renesas-soc, Chien Nguyen
On Wed, Sep 25, 2019 at 02:43:27PM -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")
> Reported-by: Chien Nguyen <chien.nguyen.eb@rvc.renesas.com>
> Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
> ---
> 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 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;
> --
> 2.23.0
>
<formletter>
This is not the correct way to submit patches for inclusion in the
stable kernel tree. Please read:
https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.
</formletter>
^ permalink raw reply [flat|nested] 2+ messages in thread
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