Re: [PATCH] platform/chrome: cros_ec_lightbar: Check if ec supports suspend commands

Benson Leung
2025-10-30T20:17:49Z

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On Thu, Oct 23, 2025 at 07:42:40PM -0400, Brady Norander wrote:
> The Chromebook Pixel 2013 (Link)'s ec does not support the lightbar manual suspend commands.
> As a result, attempting to suspend the device fails and prints the following error:
>
> cros-ec-lightbar cros-ec-lightbar.3.auto: PM: dpm_run_callback(): platform_pm_suspend returns -22
> cros-ec-lightbar cros-ec-lightbar.3.auto: PM: failed to suspend: error -22
> PM: Some devices failed to suspend, or early wake event detected
>
> Check the return value of lb_manual_suspend_ctrl in cros_ec_lightbar_probe and disable manual
> suspend control if an error is returned.
>
> Signed-off-by: Brady Norander <bradynorander@gmail.com>

Reviewed-by: Benson Leung <bleung@chromium.org>

>
> diff --git a/drivers/platform/chrome/cros_ec_lightbar.c b/drivers/platform/chrome/cros_ec_lightbar.c
> index 87634f6921b7..1b7e4c4e18bc 100644
> --- a/drivers/platform/chrome/cros_ec_lightbar.c
> +++ b/drivers/platform/chrome/cros_ec_lightbar.c
> @@ -30,6 +30,13 @@ static unsigned long lb_interval_jiffies = 50 * HZ / 1000;
> */
> static bool userspace_control;
>
> +/*
> + * Whether or not the lightbar supports the manual suspend commands.
> + * The Pixel 2013 (Link) does not while all other devices with a
> + * lightbar do.
> +*/
> +static bool has_manual_suspend;
> +
> static ssize_t interval_msec_show(struct device *dev,
> struct device_attribute *attr, char *buf)
> {
> @@ -550,7 +557,7 @@ static int cros_ec_lightbar_probe(struct platform_device *pd)
> return -ENODEV;
>
> /* Take control of the lightbar from the EC. */
> - lb_manual_suspend_ctrl(ec_dev, 1);
> + has_manual_suspend = (lb_manual_suspend_ctrl(ec_dev, 1) >= 0);
>
> ret = sysfs_create_group(&ec_dev->class_dev.kobj,
> &cros_ec_lightbar_attr_group);
> @@ -569,14 +576,15 @@ static void cros_ec_lightbar_remove(struct platform_device *pd)
> &cros_ec_lightbar_attr_group);
>
> /* Let the EC take over the lightbar again. */
> - lb_manual_suspend_ctrl(ec_dev, 0);
> + if (has_manual_suspend)
> + lb_manual_suspend_ctrl(ec_dev, 0);
> }
>
> static int __maybe_unused cros_ec_lightbar_resume(struct device *dev)
> {
> struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
>
> - if (userspace_control)
> + if (userspace_control || !has_manual_suspend)
> return 0;
>
> return lb_send_empty_cmd(ec_dev, LIGHTBAR_CMD_RESUME);
> @@ -586,7 +594,7 @@ static int __maybe_unused cros_ec_lightbar_suspend(struct device *dev)
> {
> struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
>
> - if (userspace_control)
> + if (userspace_control || !has_manual_suspend)
> return 0;
>
> return lb_send_empty_cmd(ec_dev, LIGHTBAR_CMD_SUSPEND);
> --
> 2.51.0
>

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