Re: [PATCH v7 06/11] leds: trigger: netdev: add hardware control support

Alexander Stein
2022-12-15T15:27:30Z

Hi,

thanks for the v7 series.

Am Donnerstag, 15. Dezember 2022, 00:54:33 CET schrieb Christian Marangi:
> Add hardware control support for the Netdev trigger.
> The trigger on config change will check if the requested trigger can set
> to blink mode using LED hardware mode and if every blink mode is supported,
> the trigger will enable hardware mode with the requested configuration.
> If there is at least one trigger that is not supported and can't run in
> hardware mode, then software mode will be used instead.
> A validation is done on every value change and on fail the old value is
> restored and -EINVAL is returned.
>
> Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
> ---
> drivers/leds/trigger/ledtrig-netdev.c | 155 +++++++++++++++++++++++++-
> 1 file changed, 149 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/leds/trigger/ledtrig-netdev.c
> b/drivers/leds/trigger/ledtrig-netdev.c index dd63cadb896e..ed019cb5867c
> 100644
> --- a/drivers/leds/trigger/ledtrig-netdev.c
> +++ b/drivers/leds/trigger/ledtrig-netdev.c
> @@ -37,6 +37,7 @@
> */
>
> struct led_netdev_data {
> + enum led_blink_modes blink_mode;
> spinlock_t lock;
>
> struct delayed_work work;
> @@ -53,11 +54,105 @@ struct led_netdev_data {
> bool carrier_link_up;
> };
>
> +struct netdev_led_attr_detail {
> + char *name;
> + bool hardware_only;
> + enum led_trigger_netdev_modes bit;
> +};
> +
> +static struct netdev_led_attr_detail attr_details[] = {
> + { .name = "link", .bit = TRIGGER_NETDEV_LINK},
> + { .name = "tx", .bit = TRIGGER_NETDEV_TX},
> + { .name = "rx", .bit = TRIGGER_NETDEV_RX},
> +};
> +
> +static bool validate_baseline_state(struct led_netdev_data *trigger_data)
> +{
> + struct led_classdev *led_cdev = trigger_data->led_cdev;
> + struct netdev_led_attr_detail *detail;
> + u32 hw_blink_mode_supported = 0;
> + bool force_sw = false;
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(attr_details); i++) {
> + detail = &attr_details[i];
> +
> + /* Mode not active, skip */
> + if (!test_bit(detail->bit, &trigger_data->mode))
> + continue;
> +
> + /* Hardware only mode enabled on software controlled led
*/
> + if (led_cdev->blink_mode == SOFTWARE_CONTROLLED &&
> + detail->hardware_only)
> + return false;
> +
> + /* Check if the mode supports hardware mode */
> + if (led_cdev->blink_mode != SOFTWARE_CONTROLLED) {
> + /* With a net dev set, force software mode.
> + * With modes are handled by hardware, led will
blink
> + * based on his own events and will ignore any
event
> + * from the provided dev.
> + */
> + if (trigger_data->net_dev) {
> + force_sw = true;
> + continue;
> + }
> +
> + /* With empty dev, check if the mode is
supported */
> + if
(led_trigger_blink_mode_is_supported(led_cdev, detail->bit))
> + hw_blink_mode_supported |= BIT(detail-
>bit);

Shouldn't this be BIT(detail->bit)?

> + }
> + }
> +
> + /* We can't run modes handled by both software and hardware.
> + * Check if we run hardware modes and check if all the modes
> + * can be handled by hardware.
> + */
> + if (hw_blink_mode_supported && hw_blink_mode_supported !=
> trigger_data->mode) + return false;
> +
> + /* Modes are valid. Decide now the running mode to later
> + * set the baseline.
> + * Software mode is enforced with net_dev set. With an empty
> + * one hardware mode is selected by default (if supported).
> + */
> + if (force_sw || led_cdev->blink_mode == SOFTWARE_CONTROLLED)

IMHO '|| !hw_blink_mode_supported' should be added here for blink_modes. This
might happen if a PHY LED is SOFTWARE_HARDWARE_CONTROLLED, but some blink mode
is not supported by hardware, thus hw_blink_mode_supported=0.

Best regards,
Alexander

> + trigger_data->blink_mode = SOFTWARE_CONTROLLED;
> + else
> + trigger_data->blink_mode = HARDWARE_CONTROLLED;
> +
> + return true;
> +}
> +
> static void set_baseline_state(struct led_netdev_data *trigger_data)
> {
> + int i;
> int current_brightness;
> + struct netdev_led_attr_detail *detail;
> struct led_classdev *led_cdev = trigger_data->led_cdev;
>
> + /* Modes already validated. Directly apply hw trigger modes */
> + if (trigger_data->blink_mode == HARDWARE_CONTROLLED) {
> + /* We are refreshing the blink modes. Reset them */
> + led_cdev->hw_control_configure(led_cdev,
BIT(TRIGGER_NETDEV_LINK),
> + BLINK_MODE_ZERO);
> +
> + for (i = 0; i < ARRAY_SIZE(attr_details); i++) {
> + detail = &attr_details[i];
> +
> + if (!test_bit(detail->bit, &trigger_data->mode))
> + continue;
> +
> + led_cdev->hw_control_configure(led_cdev,
BIT(detail->bit),
> +
BLINK_MODE_ENABLE);

Shouldn't this be BIT(detail->bit)?

> + }
> +
> + led_cdev->hw_control_start(led_cdev);
> +
> + return;
> + }
> +
> + /* Handle trigger modes by software */
> current_brightness = led_cdev->brightness;
> if (current_brightness)
> led_cdev->blink_brightness = current_brightness;
> @@ -100,10 +195,15 @@ static ssize_t device_name_store(struct device *dev,
> size_t size)
> {
> struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
> + struct net_device *old_net = trigger_data->net_dev;
> + char old_device_name[IFNAMSIZ];
>
> if (size >= IFNAMSIZ)
> return -EINVAL;
>
> + /* Backup old device name */
> + memcpy(old_device_name, trigger_data->device_name, IFNAMSIZ);
> +
> cancel_delayed_work_sync(&trigger_data->work);
>
> spin_lock_bh(&trigger_data->lock);
> @@ -122,6 +222,19 @@ static ssize_t device_name_store(struct device *dev,
> trigger_data->net_dev =
> dev_get_by_name(&init_net, trigger_data->device_name);
>
> + if (!validate_baseline_state(trigger_data)) {
> + /* Restore old net_dev and device_name */
> + if (trigger_data->net_dev)
> + dev_put(trigger_data->net_dev);
> +
> + dev_hold(old_net);
> + trigger_data->net_dev = old_net;
> + memcpy(trigger_data->device_name, old_device_name,
IFNAMSIZ);
> +
> + spin_unlock_bh(&trigger_data->lock);
> + return -EINVAL;
> + }
> +
> trigger_data->carrier_link_up = false;
> if (trigger_data->net_dev != NULL)
> trigger_data->carrier_link_up =
netif_carrier_ok(trigger_data->net_dev);
> @@ -159,7 +272,7 @@ static ssize_t netdev_led_attr_store(struct device *dev,
> const char *buf, size_t size, enum led_trigger_netdev_modes attr)
> {
> struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
> - unsigned long state;
> + unsigned long state, old_mode = trigger_data->mode;
> int ret;
> int bit;
>
> @@ -184,6 +297,12 @@ static ssize_t netdev_led_attr_store(struct device
> *dev, const char *buf, else
> clear_bit(bit, &trigger_data->mode);
>
> + if (!validate_baseline_state(trigger_data)) {
> + /* Restore old mode on validation fail */
> + trigger_data->mode = old_mode;
> + return -EINVAL;
> + }
> +
> set_baseline_state(trigger_data);
>
> return size;
> @@ -220,6 +339,8 @@ static ssize_t interval_store(struct device *dev,
> size_t size)
> {
> struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
> + int old_interval = atomic_read(&trigger_data->interval);
> + u32 old_mode = trigger_data->mode;
> unsigned long value;
> int ret;
>
> @@ -228,13 +349,22 @@ static ssize_t interval_store(struct device *dev,
> return ret;
>
> /* impose some basic bounds on the timer interval */
> - if (value >= 5 && value <= 10000) {
> - cancel_delayed_work_sync(&trigger_data->work);
> + if (value < 5 || value > 10000)
> + return -EINVAL;
> +
> + cancel_delayed_work_sync(&trigger_data->work);
> +
> + atomic_set(&trigger_data->interval, msecs_to_jiffies(value));
>
> - atomic_set(&trigger_data->interval,
msecs_to_jiffies(value));
> - set_baseline_state(trigger_data); /* resets timer
*/
> + if (!validate_baseline_state(trigger_data)) {
> + /* Restore old interval on validation error */
> + atomic_set(&trigger_data->interval, old_interval);
> + trigger_data->mode = old_mode;
> + return -EINVAL;
> }
>
> + set_baseline_state(trigger_data); /* resets timer */
> +
> return size;
> }
>
> @@ -368,13 +498,25 @@ static int netdev_trig_activate(struct led_classdev
> *led_cdev) trigger_data->mode = 0;
> atomic_set(&trigger_data->interval, msecs_to_jiffies(50));
> trigger_data->last_activity = 0;
> + if (led_cdev->blink_mode != SOFTWARE_CONTROLLED) {
> + /* With hw mode enabled reset any rule set by default */
> + if (led_cdev->hw_control_status(led_cdev)) {
> + rc = led_cdev->hw_control_configure(led_cdev,
BIT(TRIGGER_NETDEV_LINK),
> +
BLINK_MODE_ZERO);
> + if (rc)
> + goto err;
> + }
> + }
>
> led_set_trigger_data(led_cdev, trigger_data);
>
> rc = register_netdevice_notifier(&trigger_data->notifier);
> if (rc)
> - kfree(trigger_data);
> + goto err;
>
> + return 0;
> +err:
> + kfree(trigger_data);
> return rc;
> }
>
> @@ -394,6 +536,7 @@ static void netdev_trig_deactivate(struct led_classdev
> *led_cdev)
>
> static struct led_trigger netdev_led_trigger = {
> .name = "netdev",
> + .supported_blink_modes = SOFTWARE_HARDWARE,
> .activate = netdev_trig_activate,
> .deactivate = netdev_trig_deactivate,
> .groups = netdev_trig_groups,