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Subject: Re: [PATCH v2] scsi: ufs: sysfs: Print string descriptors as raw data
To:     Arthur Simchaev <Arthur.Simchaev@wdc.com>,
        "James E . J . Bottomley" <jejb@linux.vnet.ibm.com>,
        "Martin K . Petersen" <martin.petersen@oracle.com>,
        linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     alim.akhtar@samsung.com, Bean Huo <beanhuo@micron.com>
References: <1613410846-16883-1-git-send-email-Arthur.Simchaev@wdc.com>
From:   Bart Van Assche <bvanassche@acm.org>
Message-ID: <9ade874b-b69e-615d-b101-2ecc664ba64d@acm.org>
Date:   Tue, 16 Mar 2021 20:31:07 -0700
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On 2/15/21 9:40 AM, Arthur Simchaev wrote:
> -#define UFS_STRING_DESCRIPTOR(_name, _pname)				\
> +#define UFS_STRING_DESCRIPTOR(_name, _pname, _is_ascii)		\
>  static ssize_t _name##_show(struct device *dev,				\
>  	struct device_attribute *attr, char *buf)			\
>  {									\
> @@ -690,10 +690,18 @@ static ssize_t _name##_show(struct device *dev,				\
>  	kfree(desc_buf);						\
>  	desc_buf = NULL;						\
>  	ret = ufshcd_read_string_desc(hba, index, &desc_buf,		\
> -				      SD_ASCII_STD);			\
> +				      _is_ascii);			\
>  	if (ret < 0)							\
>  		goto out;						\
> -	ret = sysfs_emit(buf, "%s\n", desc_buf);			\
> +	if (_is_ascii) {						\
> +		ret = sysfs_emit(buf, "%s\n", desc_buf);		\
> +	} else {							\
> +		int i;							\
> +									\
> +		for (i = 0; i < desc_buf[0]; i++)			\
> +			hex_byte_pack(buf + i * 2, desc_buf[i]);	\
> +		ret = sysfs_emit(buf, "%s\n", buf);			\
> +	}			\
>  out:									\
>  	pm_runtime_put_sync(hba->dev);					\
>  	kfree(desc_buf);						\

Hex data needs to be parsed before it can be used by any software. Has
it been considered to make the "raw" attributes binary attributes
instead of hex-encoded binary? See also sysfs_create_bin_file().

Thanks,

Bart.