[PATCH v2] nvme-hwmon: consistently ignore errors from nvme_hwmon_init

[Sagi Grimberg]

> An NVMe controller works perfectly fine even when the hwmon
> initialization fails.  Stop returning errors that do not come from a
> controller reset from nvme_hwmon_init to handle this case consistently.

Maybe I'm missing something, but nvme_hwmon_init is not called
from the reset flow, only in the first init, I don't understand
how the commit msg follows the code.

> 
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> ---
> 
> Changes since v1:
>   - switch to ignoring the errors in the caller.
> 
>   drivers/nvme/host/core.c  |  6 +++++-
>   drivers/nvme/host/hwmon.c | 13 ++++++++-----
>   2 files changed, 13 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 9cbe7854d4883..dc42206005855 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -3262,8 +3262,12 @@ int nvme_init_ctrl_finish(struct nvme_ctrl *ctrl)
>   		return ret;
>   
>   	if (!ctrl->identified && !nvme_discovery_ctrl(ctrl)) {
> +		/*
> +		 * Do not return errors unless we are in a controller reset,
> +		 * the controller works perfectly fine without hwmon.
> +		 */
>   		ret = nvme_hwmon_init(ctrl);
> -		if (ret < 0)
> +		if (ret == -EINTR)
>   			return ret;
>   	}
>   
> diff --git a/drivers/nvme/host/hwmon.c b/drivers/nvme/host/hwmon.c
> index 0a586d7129201..23918bb7bdca2 100644
> --- a/drivers/nvme/host/hwmon.c
> +++ b/drivers/nvme/host/hwmon.c
> @@ -230,7 +230,7 @@ int nvme_hwmon_init(struct nvme_ctrl *ctrl)
>   
>   	data = kzalloc(sizeof(*data), GFP_KERNEL);
>   	if (!data)
> -		return 0;
> +		return -ENOMEM;
>   
>   	data->ctrl = ctrl;
>   	mutex_init(&data->read_lock);
> @@ -238,8 +238,7 @@ int nvme_hwmon_init(struct nvme_ctrl *ctrl)
>   	err = nvme_hwmon_get_smart_log(data);
>   	if (err) {
>   		dev_warn(dev, "Failed to read smart log (error %d)\n", err);
> -		kfree(data);
> -		return err;
> +		goto err_free_data;
>   	}
>   
>   	hwmon = hwmon_device_register_with_info(dev, "nvme",
> @@ -247,11 +246,15 @@ int nvme_hwmon_init(struct nvme_ctrl *ctrl)
>   						NULL);
>   	if (IS_ERR(hwmon)) {
>   		dev_warn(dev, "Failed to instantiate hwmon device\n");
> -		kfree(data);
> -		return PTR_ERR(hwmon);
> +		err = PTR_ERR(hwmon);
> +		goto err_free_data;
>   	}
>   	ctrl->hwmon_device = hwmon;
>   	return 0;
> +
> +err_free_data:
> +	kfree(data);
> +	return err;
>   }
>   
>   void nvme_hwmon_exit(struct nvme_ctrl *ctrl)