[alsa-devel] [PATCH] ASoC: nau8825: fix fake interruption when booting

[AS50 KCHsu0]

On 6/10/2019 10:18 AM, Cheng-yi Chiang wrote:
> On Mon, Jun 10, 2019 at 10:13 AM John Hsu <KCHSU0 at nuvoton.com> wrote:
>> There is no pull-up resistor at IRQ line where it connects from
>> the codec to SoC. When booting, the signal of IRQ pin will keep low
>> which makes the SoC invoke the ISR repeatedly because the IRQ is
>> registered trigger low. It will not stop until the codec sets up
>> the interruption and pulls the signal high. In the patch,
>> nau8825 will internally pull the signal to high at booting in case
>> the fake interrupts happen.
>>
>> The patch help to fix the issue as follows:
>> Google issue 133904101: Cave: excessive number of interrupts before Nau8825 codec is initialized
>> Reported Issue
>> Chrome OS Version  :  ChromeOS R76-12217.0.0
>> Type of hardware   :
>>
>> What steps will reproduce the problem?
>> Boot device
>> What is the expected output?
>> A lot of interrupts without any events
>> What do you see instead?
>> The fake interrupts are gone
>>
>> How frequently does this problem reproduce?
>> Always
>>
>> What is the impact to the user, and is there a workaround?
>> If so, what is it?
>>
>> BUG=b:133904101
>> TEST=Boot device, and then check the interrupts are real.
>>
>> Signed-off-by: John Hsu <KCHSU0 at nuvoton.com>
> Tested-by: Cheng-Yi Chiang <cychiang at chromium.org>
>
> Thank you for the fix.
> I think you can remove the description about issue 133904101 in the
> commit messages and BUG and TEST fields.
>

OK, I will remove it later.


>
>
>> ---
>>   sound/soc/codecs/nau8825.c | 4 ++++
>>   sound/soc/codecs/nau8825.h | 2 ++
>>   2 files changed, 6 insertions(+)
>>
>> diff --git a/sound/soc/codecs/nau8825.c b/sound/soc/codecs/nau8825.c
>> index 47e65cf99879..83ec841f7865 100644
>> --- a/sound/soc/codecs/nau8825.c
>> +++ b/sound/soc/codecs/nau8825.c
>> @@ -1881,6 +1881,10 @@ static void nau8825_init_regs(struct nau8825 *nau8825)
>>                  NAU8825_JACK_EJECT_DEBOUNCE_MASK,
>>                  nau8825->jack_eject_debounce << NAU8825_JACK_EJECT_DEBOUNCE_SFT);
>>
>> +       /* Pull up IRQ pin */
>> +       regmap_update_bits(regmap, NAU8825_REG_INTERRUPT_MASK,
>> +               NAU8825_IRQ_PIN_PULLUP | NAU8825_IRQ_PIN_PULL_EN,
>> +               NAU8825_IRQ_PIN_PULLUP | NAU8825_IRQ_PIN_PULL_EN);
>>          /* Mask unneeded IRQs: 1 - disable, 0 - enable */
>>          regmap_update_bits(regmap, NAU8825_REG_INTERRUPT_MASK, 0x7ff, 0x7ff);
>>
>> diff --git a/sound/soc/codecs/nau8825.h b/sound/soc/codecs/nau8825.h
>> index f6074c618569..3f41897ed3f6 100644
>> --- a/sound/soc/codecs/nau8825.h
>> +++ b/sound/soc/codecs/nau8825.h
>> @@ -171,6 +171,8 @@
>>   #define NAU8825_JACK_POLARITY  (1 << 1) /* 0 - active low, 1 - active high */
>>
>>   /* INTERRUPT_MASK (0xf) */
>> +#define NAU8825_IRQ_PIN_PULLUP (1 << 14)
>> +#define NAU8825_IRQ_PIN_PULL_EN (1 << 13)
>>   #define NAU8825_IRQ_OUTPUT_EN (1 << 11)
>>   #define NAU8825_IRQ_HEADSET_COMPLETE_EN (1 << 10)
>>   #define NAU8825_IRQ_RMS_EN (1 << 8)
>> --
>> 2.21.0
>>


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