Re: [PATCH 21/22] libata: implement ATA printk helpers

[Tejun Heo <htejun@gmail.com>]

Albert Lee wrote:
> Tejun Heo wrote:
>> Implement ata_{port|dev}_printk() which prefixes the message with
>> proper identification string.  This change is necessary for later PM
>> support because devices and links should be identified differently
>> depending on how they are attached.
>>
>> This also helps unifying device id strings.  Currently, there are two
>> forms in use (P is the port number D device number) - 'ataP(D):', and
>> 'ataP: dev D '.  These macros also make it harder to forget proper ID
>> string (e.g. printing only port number when a device is in question).
>>
>> Debug message handling can be integrated into these printk macros by
>> passing debug type and level via @lv.
>>
>> Signed-off-by: Tejun Heo <htejun@gmail.com>
>>
>> ---
>>
>>  include/linux/libata.h |   11 +++++++++++
>>  1 files changed, 11 insertions(+), 0 deletions(-)
>>
>> 387b4ba08bdce6d729cf441e7c1173d9863f4c04
>> diff --git a/include/linux/libata.h b/include/linux/libata.h
>> index bd8cd3b..7b54d92 100644
>> --- a/include/linux/libata.h
>> +++ b/include/linux/libata.h
>> @@ -650,7 +650,18 @@ extern void ata_eng_timeout(struct ata_p
>>  extern void ata_eh_qc_complete(struct ata_queued_cmd *qc);
>>  extern void ata_eh_qc_retry(struct ata_queued_cmd *qc);
>>  
>> +/*
>> + * printk helpers
>> + */
>> +#define ata_port_printk(ap, lv, fmt, args...) \
>> +	printk(lv"ata%u: "fmt, (ap)->id , ##args)
>> +
>> +#define ata_dev_printk(dev, lv, fmt, args...) \
>> +	printk(lv"ata%u.%02u: "fmt, (dev)->ap->id, (dev)->devno , ##args)
>>  
>> +/*
>> + * qc helpers
>> + */
>>  static inline int
>>  ata_sg_is_last(struct scatterlist *sg, struct ata_queued_cmd *qc)
>>  {
> 
> A minor question:
> Messages like "ata5.01" are seen in the log. Do we ever have more than 2 devices per port?
> (with port multiplier?) Otherwise, maybe "ata5.1" is shorter?

Yes, the Port Multiplier control port is always device #15.  I thought 
it would be confusing to see messages where "ata5.3:" and "ata5.15:" are 
mixed, so the "%02d".

-- 
tejun