Re: [PATCH 2/2] hwmon: (pmbus/ibm-cffps) Fix LED blink behavior

Guenter Roeck
2019-11-06T22:38:12Z

On Wed, Nov 06, 2019 at 02:01:06PM -0600, Eddie James wrote:
> The LED blink_set function incorrectly did not tell the PSU LED to blink
> if brightness was LED_OFF. Fix this, and also correct the LED_OFF
> command data, which should give control of the LED back to the PSU
> firmware. Also prevent I2C failures from getting the driver LED state
> out of sync and add some dev_dbg statements.
>
> Signed-off-by: Eddie James <eajames@linux.ibm.com>

Applied.

Thanks,
Guenter

> ---
> drivers/hwmon/pmbus/ibm-cffps.c | 27 +++++++++++++++++++--------
> 1 file changed, 19 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/hwmon/pmbus/ibm-cffps.c b/drivers/hwmon/pmbus/ibm-cffps.c
> index c6a00e83aac6..d359b76bcb36 100644
> --- a/drivers/hwmon/pmbus/ibm-cffps.c
> +++ b/drivers/hwmon/pmbus/ibm-cffps.c
> @@ -44,9 +44,13 @@
> #define CFFPS_MFR_VAUX_FAULT BIT(6)
> #define CFFPS_MFR_CURRENT_SHARE_WARNING BIT(7)
>
> +/*
> + * LED off state actually relinquishes LED control to PSU firmware, so it can
> + * turn on the LED for faults.
> + */
> +#define CFFPS_LED_OFF 0
> #define CFFPS_LED_BLINK BIT(0)
> #define CFFPS_LED_ON BIT(1)
> -#define CFFPS_LED_OFF BIT(2)
> #define CFFPS_BLINK_RATE_MS 250
>
> enum {
> @@ -301,23 +305,31 @@ static int ibm_cffps_led_brightness_set(struct led_classdev *led_cdev,
> enum led_brightness brightness)
> {
> int rc;
> + u8 next_led_state;
> struct ibm_cffps *psu = container_of(led_cdev, struct ibm_cffps, led);
>
> if (brightness == LED_OFF) {
> - psu->led_state = CFFPS_LED_OFF;
> + next_led_state = CFFPS_LED_OFF;
> } else {
> brightness = LED_FULL;
> +
> if (psu->led_state != CFFPS_LED_BLINK)
> - psu->led_state = CFFPS_LED_ON;
> + next_led_state = CFFPS_LED_ON;
> + else
> + next_led_state = CFFPS_LED_BLINK;
> }
>
> + dev_dbg(&psu->client->dev, "LED brightness set: %d. Command: %d.\n",
> + brightness, next_led_state);
> +
> pmbus_set_page(psu->client, 0);
>
> rc = i2c_smbus_write_byte_data(psu->client, CFFPS_SYS_CONFIG_CMD,
> - psu->led_state);
> + next_led_state);
> if (rc < 0)
> return rc;
>
> + psu->led_state = next_led_state;
> led_cdev->brightness = brightness;
>
> return 0;
> @@ -330,10 +342,7 @@ static int ibm_cffps_led_blink_set(struct led_classdev *led_cdev,
> int rc;
> struct ibm_cffps *psu = container_of(led_cdev, struct ibm_cffps, led);
>
> - psu->led_state = CFFPS_LED_BLINK;
> -
> - if (led_cdev->brightness == LED_OFF)
> - return 0;
> + dev_dbg(&psu->client->dev, "LED blink set.\n");
>
> pmbus_set_page(psu->client, 0);
>
> @@ -342,6 +351,8 @@ static int ibm_cffps_led_blink_set(struct led_classdev *led_cdev,
> if (rc < 0)
> return rc;
>
> + psu->led_state = CFFPS_LED_BLINK;
> + led_cdev->brightness = LED_FULL;
> *delay_on = CFFPS_BLINK_RATE_MS;
> *delay_off = CFFPS_BLINK_RATE_MS;
>