Re: [PATCH v3 7/7] extcon: arizona: Improve headphone detection error handling

Chanwoo Choi
2013-11-15T00:54:08Z

Hi Charles,

On 11/15/2013 01:18 AM, Charles Keepax wrote:
> In several places the return value of regmap operations is not checked
> whilst handling headphone detection. This patch adds checks for these
> return values. Additionally, failing to read/write a register is a
> serious enough error we should abort the headphone detection process so
> correct a couple of cases where this was not the case.
>
> Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
> ---
> drivers/extcon/extcon-arizona.c | 82 ++++++++++++++++++++++++++++----------
> 1 files changed, 60 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/extcon/extcon-arizona.c b/drivers/extcon/extcon-arizona.c
> index d71a738..321dcc9 100644
> --- a/drivers/extcon/extcon-arizona.c
> +++ b/drivers/extcon/extcon-arizona.c
> @@ -399,22 +399,32 @@ static int arizona_hpdet_read_ip1(struct arizona_extcon_info *info)
> ret = regmap_read(arizona->regmap, ARIZONA_HP_DACVAL, &val);
> if (ret != 0) {

I prefer following checking statement
if (ret < 0) instead of if (ret != 0)

> dev_err(arizona->dev, "Failed to read HP value: %d\n", ret);
> - return -EAGAIN;
> + return ret;
> }
>
> - regmap_read(arizona->regmap, ARIZONA_HEADPHONE_DETECT_1, &range);
> + ret = regmap_read(arizona->regmap, ARIZONA_HEADPHONE_DETECT_1, &range);
> range = (range & ARIZONA_HP_IMPEDANCE_RANGE_MASK)
> >> ARIZONA_HP_IMPEDANCE_RANGE_SHIFT;

I prefer to move 'range operation' statement after checking ret value.

> + if (ret != 0) {

ditto.

> + dev_err(arizona->dev, "Failed to read HP range: %d\n", ret);
> + return ret;
> + }
>
> if (range < ARRAY_SIZE(arizona_hpdet_b_ranges) - 1 &&
> (val < 100 || val >= 0x3fb)) {
> range++;
> dev_dbg(arizona->dev, "Moving to HPDET range %d\n", range);
> - regmap_update_bits(arizona->regmap,
> - ARIZONA_HEADPHONE_DETECT_1,
> - ARIZONA_HP_IMPEDANCE_RANGE_MASK,
> - range <<
> - ARIZONA_HP_IMPEDANCE_RANGE_SHIFT);
> + ret = regmap_update_bits(arizona->regmap,
> + ARIZONA_HEADPHONE_DETECT_1,
> + ARIZONA_HP_IMPEDANCE_RANGE_MASK,
> + range <<
> + ARIZONA_HP_IMPEDANCE_RANGE_SHIFT);
> + if (ret != 0) {

ditto.

> + dev_err(arizona->dev,
> + "Failed to move range (%d): %d\n",
> + range, ret);
> + return ret;
> + }
> return -EAGAIN;

If below statement is true, arizona_hpdet_read_ip1 always return error?
This if statement return either 'ret' or '-EAGAIN'.

if (range < ARRAY_SIZE(arizona_hpdet_b_ranges) - 1 &&
(val < 100 || val >= 0x3fb)) {

> }
>
> @@ -454,7 +464,11 @@ static int arizona_hpdet_read_ip2(struct arizona_extcon_info *info)
> /* Convert to ohms, the value is in 0.5 ohm increments */
> val /= 2;
>
> - regmap_read(arizona->regmap, ARIZONA_HEADPHONE_DETECT_1, &range);
> + ret = regmap_read(arizona->regmap, ARIZONA_HEADPHONE_DETECT_1, &range);
> + if (ret != 0) {

ditto.

> + dev_err(arizona->dev, "Failed to read HP range: %d\n", ret);
> + return ret;
> + }
> range = (range & ARIZONA_HP_IMPEDANCE_RANGE_MASK)
> >> ARIZONA_HP_IMPEDANCE_RANGE_SHIFT;
>
> @@ -465,11 +479,17 @@ static int arizona_hpdet_read_ip2(struct arizona_extcon_info *info)
> dev_dbg(arizona->dev, "Moving to HPDET range %d-%d\n",
> arizona_hpdet_c_ranges[range].min,
> arizona_hpdet_c_ranges[range].max);
> - regmap_update_bits(arizona->regmap,
> + ret = regmap_update_bits(arizona->regmap,
> ARIZONA_HEADPHONE_DETECT_1,
> ARIZONA_HP_IMPEDANCE_RANGE_MASK,
> range <<
> ARIZONA_HP_IMPEDANCE_RANGE_SHIFT);
> + if (ret != 0) {

ditto.

> + dev_err(arizona->dev,
> + "Failed to move range (%d): %d\n",
> + range, ret);
> + return ret;
> + }
> return -EAGAIN;

ditto.

> }
>
> @@ -519,6 +539,7 @@ static int arizona_hpdet_do_id(struct arizona_extcon_info *info, int *reading,
> {
> struct arizona *arizona = info->arizona;
> int id_gpio = arizona->pdata.hpdet_id_gpio;
> + int ret;
>
> /*
> * If we're using HPDET for accessory identification we need
> @@ -531,18 +552,30 @@ static int arizona_hpdet_do_id(struct arizona_extcon_info *info, int *reading,
> if (id_gpio && info->num_hpdet_res == 1) {
> dev_dbg(arizona->dev, "Measuring mic\n");
>
> - regmap_update_bits(arizona->regmap,
> - ARIZONA_ACCESSORY_DETECT_MODE_1,
> - ARIZONA_ACCDET_MODE_MASK |
> - ARIZONA_ACCDET_SRC,
> - ARIZONA_ACCDET_MODE_HPR |
> - info->micd_modes[0].src);
> + ret = regmap_update_bits(arizona->regmap,
> + ARIZONA_ACCESSORY_DETECT_MODE_1,
> + ARIZONA_ACCDET_MODE_MASK |
> + ARIZONA_ACCDET_SRC,
> + ARIZONA_ACCDET_MODE_HPR |
> + info->micd_modes[0].src);
> + if (ret != 0) {
> + dev_err(arizona->dev,
> + "Failed to change HPDET source: %d\n",
> + ret);
> + return ret;
> + }
>
> gpio_set_value_cansleep(id_gpio, 1);
>
> - regmap_update_bits(arizona->regmap,
> - ARIZONA_HEADPHONE_DETECT_1,
> - ARIZONA_HP_POLL, ARIZONA_HP_POLL);
> + ret = regmap_update_bits(arizona->regmap,
> + ARIZONA_HEADPHONE_DETECT_1,
> + ARIZONA_HP_POLL, ARIZONA_HP_POLL);
> + if (ret != 0) {
> + dev_err(arizona->dev,
> + "Failed to re-enable HPDET: %d\n",
> + ret);
> + return ret;
> + }
> return -EAGAIN;

Always return error?

> }
>
> @@ -575,10 +608,15 @@ static int arizona_hpdet_do_id(struct arizona_extcon_info *info, int *reading,
> }
>
> /* Make sure everything is reset back to the real polarity */
> - regmap_update_bits(arizona->regmap,
> - ARIZONA_ACCESSORY_DETECT_MODE_1,
> - ARIZONA_ACCDET_SRC,
> - info->micd_modes[0].src);
> + ret = regmap_update_bits(arizona->regmap,
> + ARIZONA_ACCESSORY_DETECT_MODE_1,
> + ARIZONA_ACCDET_SRC,
> + info->micd_modes[0].src);
> + if (ret != 0) {

ditto.

> + dev_err(arizona->dev, "Failed to reset polarity: %d\n",
> + ret);
> + return ret;
> + }
> }
>
> return 0;
>

Thanks,
Chanwoo Choi