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

[Damien Le Moal <Damien.LeMoal@wdc.com>]

On 2021/08/06 18:07, Hannes Reinecke wrote:
> 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?

That would reverse the order of the messages... And I wanted to avoid having an
"if (ata_id_has_lba(id))" again just for the print. Moving the 2 ata_dev_info()
calls into the respective functions was the other solution I tried, but then the
functions require *a lot* more arguments (revbuf, modelbuf, fwrevbuf, ...) wich
was not super nice.

This one is the least ugly I thought... Any other idea ?

> 
> Cheers,
> 
> Hannes
> 


-- 
Damien Le Moal
Western Digital Research