Re: [PATCH v2 2/2] scsi: ufs: core: Add a sysfs entry for ufshcd_state

[Bart Van Assche <bvanassche@acm.org>]

On 2/24/26 6:29 PM, Can Guo wrote:
> +What:		/sys/bus/platform/drivers/ufshcd/*/ufshcd_state
> +What:		/sys/bus/platform/devices/*.ufs/ufshcd_state
> +Date:		February 2026
> +Contact:	Can Guo <can.guo@oss.qualcomm.com>
> +Description:
> +		This attribute shows the state of ufshcd.
> +
> +		The attribute is read only.

Please expand "state of ufshcd", e.g. into "state of the UFS host 
controller driver".

> +static const char * const ufshcd_states[] = {
> +	[UFSHCD_STATE_RESET]			= "reset",
> +	[UFSHCD_STATE_OPERATIONAL]		= "operational",
> +	[UFSHCD_STATE_EH_SCHEDULED_NON_FATAL]	= "eh_scheduled_non_fatal",
> +	[UFSHCD_STATE_EH_SCHEDULED_FATAL]	= "eh_scheduled_fatal",
> +	[UFSHCD_STATE_ERROR]			= "error",
> +};

Please follow the kernel coding style with regard to spaces around "*".

> +static ssize_t ufshcd_state_show(struct device *dev,
> +				 struct device_attribute *attr, char *buf)
> +{
> +	struct ufs_hba *hba = dev_get_drvdata(dev);
> +
> +	return sysfs_emit(buf, "%s\n", ufshcd_states[hba->ufshcd_state]);
> +}

In the above function, please check that hba->ufshcd_state does not 
exceed the bounds of the ufshcd_states[] array and also that
ufshcd_states[hba->ufshcd_state] is not NULL.

> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index c6c7de7a0603..32a508e1582e 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -7917,6 +7917,8 @@ static void ufshcd_process_probe_result(struct ufs_hba *hba,
>   		hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL;
>   	spin_unlock_irqrestore(hba->host->host_lock, flags);
>   
> +	sysfs_notify(&hba->dev->kobj, NULL, "ufshcd_state");
> +
>   	trace_ufshcd_init(hba, ret,
>   			  ktime_to_us(ktime_sub(ktime_get(), probe_start)),
>   			  hba->curr_dev_pwr_mode, hba->uic_link_state);

Shouldn't there be one sysfs_notify(&hba->dev->kobj, NULL, 
"ufshcd_state") call after every hba->ufshcd_state change?

Thanks,

Bart.