Re: [PATCH v10] ufs: core: Add WB buffer resize support

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

On 4/7/25 2:09 AM, Huan Tang wrote:
> +What:		/sys/bus/platform/drivers/ufshcd/*/device_descriptor/ext_wb_sup
> +What:		/sys/bus/platform/devices/*.ufs/device_descriptor/ext_wb_sup
> +Date:		April 2025
> +Contact:	Huan Tang <tanghuan@vivo.com>
> +Description:
> +		This file shows extended WriteBooster features supported by
> +		the device.
> +
> +		The file is read only.

Please remove this attribute again. I don't think that it is useful to
make the value of wExtendedWriteBoosterSupport available in sysfs.
Additionally, wExtendedWriteBoosterSupport is a bitfield and hence
exporting it directly violates the sysfs one-value-per-attribute rule.

> +What:		/sys/bus/platform/drivers/ufshcd/*/attributes/wb_resize_status
> +What:		/sys/bus/platform/devices/*.ufs/attributes/wb_resize_status
> +Date:		April 2025
> +Contact:	Huan Tang <tanghuan@vivo.com>
> +Description:
> +		The host can check the resize operation status of the WriteBooster
> +		buffer by reading this attribute.
> +
> +		================  ========================================
> +		idle              Resize operation is not issued
> +		in_progress       Resize operation in progress
> +		complete_success  Resize operation completed successfully
> +		general_fail      Resize operation general failure
> +		================  ========================================

Why "general_fail" instead of "general_failure"?

> +static const char * const wb_resize_en_mode[] = {
> +	[WB_RESIZE_EN_IDLE]		= "idle",
> +	[WB_RESIZE_EN_DECREASE]		= "decrease",
> +	[WB_RESIZE_EN_INCREASE]		= "increase",
> +};

A minor comment: please remove one tab in front of "=" for the value
assignments in the above array definition.

> +static ssize_t wb_resize_hint_show(struct device *dev,
> +				struct device_attribute *attr, char *buf)
> +{
> +	struct ufs_hba *hba = dev_get_drvdata(dev);
> +	int ret;
> +	u32 value;
> +
> +	ret = wb_read_resize_attrs(hba,
> +			QUERY_ATTR_IDN_WB_BUF_RESIZE_HINT, &value);
> +	if (ret)
> +		goto out;
> +
> +	ret = sysfs_emit(buf, "%s\n", ufs_wb_resize_hint_to_string(value));
> +
> +out:
> +	return ret;
> +}

The formatting of the above code is not compliant with the Linux kernel 
coding style guide. Please reformat this patch, e.g. with "git 
clang-format HEAD^".

Otherwise this patch looks good to me.

Thanks,

Bart.