Re: [PATCH v2 4/9] libata: cleanup ata_dev_configure()

[Hannes Reinecke <hare@suse.de>]

On 8/6/21 9:42 AM, Damien Le Moal wrote:
> Introduce the helper functions ata_dev_config_lba() and
> ata_dev_config_chs() to configure the addressing capabilities of a
> device. Each helper takes a string as argument for the addressing
> information printed after these helpers execution completes.
> 
> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
> ---
>  drivers/ata/libata-core.c | 110 ++++++++++++++++++++------------------
>  1 file changed, 59 insertions(+), 51 deletions(-)
> 
> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> index b13194432e5a..2b6054cdd8fc 100644
> --- a/drivers/ata/libata-core.c
> +++ b/drivers/ata/libata-core.c
> @@ -2363,6 +2363,52 @@ static void ata_dev_config_trusted(struct ata_device *dev)
>  		dev->flags |= ATA_DFLAG_TRUSTED;
>  }
>  
> +static int ata_dev_config_lba(struct ata_device *dev,
> +			      char *info, size_t infosz)
> +{
> +	const u16 *id = dev->id;
> +	int info_ofst;
> +
> +	dev->flags |= ATA_DFLAG_LBA;
> +
> +	if (ata_id_has_lba48(id)) {
> +		dev->flags |= ATA_DFLAG_LBA48;
> +		strscpy(info, "LBA48 ", infosz);
> +
> +		if (dev->n_sectors >= (1UL << 28) &&
> +		    ata_id_has_flush_ext(id))
> +			dev->flags |= ATA_DFLAG_FLUSH_EXT;
> +	} else {
> +		strscpy(info, "LBA ", infosz);
> +	}
> +	info_ofst = strlen(info);
> +
> +	/* config NCQ */
> +	return ata_dev_config_ncq(dev, info + info_ofst,
> +				  infosz - info_ofst);
> +}
> +
> +static void ata_dev_config_chs(struct ata_device *dev,
> +			       char *info, size_t infosz)
> +{
> +	const u16 *id = dev->id;
> +
> +	/* Default translation */
> +	dev->cylinders	= id[1];
> +	dev->heads	= id[3];
> +	dev->sectors	= id[6];
> +
> +	if (ata_id_current_chs_valid(id)) {
> +		/* Current CHS translation is valid. */
> +		dev->cylinders = id[54];
> +		dev->heads     = id[55];
> +		dev->sectors   = id[56];
> +	}
> +
> +	snprintf(info, infosz, "CHS %u/%u/%u",
> +		 dev->cylinders, dev->heads, dev->sectors);
> +}
> +
>  static void ata_dev_config_devslp(struct ata_device *dev)
>  {
>  	u8 *sata_setting = dev->link->ap->sector_buf;
> @@ -2418,6 +2464,7 @@ int ata_dev_configure(struct ata_device *dev)
>  	char revbuf[7];		/* XYZ-99\0 */
>  	char fwrevbuf[ATA_ID_FW_REV_LEN+1];
>  	char modelbuf[ATA_ID_PROD_LEN+1];
> +	char lba_info[40];
>  	int rc;
>  
>  	if (!ata_dev_enabled(dev) && ata_msg_info(ap)) {
> @@ -2539,61 +2586,22 @@ int ata_dev_configure(struct ata_device *dev)
>  		}
>  
>  		if (ata_id_has_lba(id)) {
> -			const char *lba_desc;
> -			char ncq_desc[24];
> -
> -			lba_desc = "LBA";
> -			dev->flags |= ATA_DFLAG_LBA;
> -			if (ata_id_has_lba48(id)) {
> -				dev->flags |= ATA_DFLAG_LBA48;
> -				lba_desc = "LBA48";
> -
> -				if (dev->n_sectors >= (1UL << 28) &&
> -				    ata_id_has_flush_ext(id))
> -					dev->flags |= ATA_DFLAG_FLUSH_EXT;
> -			}
> -
> -			/* config NCQ */
> -			rc = ata_dev_config_ncq(dev, ncq_desc, sizeof(ncq_desc));
> +			rc = ata_dev_config_lba(dev, lba_info, sizeof(lba_info));
>  			if (rc)
>  				return rc;
> -
> -			/* print device info to dmesg */
> -			if (ata_msg_drv(ap) && print_info) {
> -				ata_dev_info(dev, "%s: %s, %s, max %s\n",
> -					     revbuf, modelbuf, fwrevbuf,
> -					     ata_mode_string(xfer_mask));
> -				ata_dev_info(dev,
> -					     "%llu sectors, multi %u: %s %s\n",
> -					(unsigned long long)dev->n_sectors,
> -					dev->multi_count, lba_desc, ncq_desc);
> -			}
>  		} else {
> -			/* CHS */
> -
> -			/* Default translation */
> -			dev->cylinders	= id[1];
> -			dev->heads	= id[3];
> -			dev->sectors	= id[6];
> -
> -			if (ata_id_current_chs_valid(id)) {
> -				/* Current CHS translation is valid. */
> -				dev->cylinders = id[54];
> -				dev->heads     = id[55];
> -				dev->sectors   = id[56];
> -			}
> +			ata_dev_config_chs(dev, lba_info, sizeof(lba_info));
> +		}
>  
> -			/* print device info to dmesg */
> -			if (ata_msg_drv(ap) && print_info) {
> -				ata_dev_info(dev, "%s: %s, %s, max %s\n",
> -					     revbuf,	modelbuf, fwrevbuf,
> -					     ata_mode_string(xfer_mask));
> -				ata_dev_info(dev,
> -					     "%llu sectors, multi %u, CHS %u/%u/%u\n",
> -					     (unsigned long long)dev->n_sectors,
> -					     dev->multi_count, dev->cylinders,
> -					     dev->heads, dev->sectors);
> -			}
> +		/* print device info to dmesg */
> +		if (ata_msg_drv(ap) && print_info) {
> +			ata_dev_info(dev, "%s: %s, %s, max %s\n",
> +				     revbuf, modelbuf, fwrevbuf,
> +				     ata_mode_string(xfer_mask));
> +			ata_dev_info(dev,
> +				     "%llu sectors, multi %u, %s\n",
> +				     (unsigned long long)dev->n_sectors,
> +				     dev->multi_count, lba_info);
>  		}
>  
>  		ata_dev_config_devslp(dev);
> 
Hmm. Can't say I like it.
Can't you move the second 'ata_dev_info()' call into the respective
functions, and kill the temporary buffer?

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		           Kernel Storage Architect
hare@suse.de			                  +49 911 74053 688
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