Hi Charles,
On 2017년 01월 24일 19:17, Charles Keepax wrote:
> As the HPDET can't be aborted mid way through we should not allow any new
> insertion to be processed until the previous HPDET has finished. It is very
> unlikely but with low enough debounce settings you could start a new HPDET
> before the old one has completed, which results in an erroneous reading.
>
> Signed-off-by: Charles Keepax <ckee...@opensource.wolfsonmicro.com>
> ---
> drivers/extcon/extcon-arizona.c | 35 +++++++++++++++++++++++++++++++++++
> 1 file changed, 35 insertions(+)
>
> diff --git a/drivers/extcon/extcon-arizona.c b/drivers/extcon/extcon-arizona.c
> index ed78b7c..218e378 100644
> --- a/drivers/extcon/extcon-arizona.c
> +++ b/drivers/extcon/extcon-arizona.c
> @@ -1049,6 +1049,39 @@ static void arizona_hpdet_work(struct work_struct
> *work)
> mutex_unlock(&info->lock);
> }
>
> +static int arizona_hpdet_wait(struct arizona_extcon_info *info)
> +{
> + struct arizona *arizona = info->arizona;
> + unsigned int val;
> + int i, ret;
> +
> + for (i = 0; i < 15; i++) {
I recommend that you define the separate constant definition
instead of using interger value (15) directly as following:
#define HPDET_WAIT_COUNT 15
> + ret = regmap_read(arizona->regmap, ARIZONA_HEADPHONE_DETECT_2,
> + &val);
> + if (ret) {
> + dev_err(arizona->dev,
> + "Failed to read HPDET state: %d\n", ret);
> + return ret;
> + }
> +
> + switch (info->hpdet_ip_version) {
> + case 0:
> + if (val & ARIZONA_HP_DONE)
> + return 0;
> + break;
> + default:
> + if (val & ARIZONA_HP_DONE_B)
> + return 0;
> + break;
> + }
> +
> + msleep(20);
ditto.
#define HPDET_WAIT_DELAY_MS 20
> + }
> +
> + dev_err(arizona->dev, "HPDET did not appear to complete\n");
> + return -ETIMEDOUT;
> +}
> +
> static irqreturn_t arizona_jackdet(int irq, void *data)
> {
> struct arizona_extcon_info *info = data;
> @@ -1155,6 +1188,8 @@ static irqreturn_t arizona_jackdet(int irq, void *data)
> "Removal report failed: %d\n", ret);
> }
>
Sometimes I met this similiar case on specific h/w.
I agree to add some delay according to the h/w.
So, you better to add the detailed comment before
calling the arizona_hpdet_wait() to make it easy
to understand why it is necessary.
> + arizona_hpdet_wait(info);
Is not necessary to check the return value of this call?
When arizona_hpdet_wait() return the -ETIMEDOUT,
Does not this error affect the next some code?
> +
> regmap_update_bits(arizona->regmap,
> ARIZONA_JACK_DETECT_DEBOUNCE,
> ARIZONA_MICD_CLAMP_DB | ARIZONA_JD1_DB,
>
--
Best Regards,
Chanwoo Choi
Samsung Electronics
