Re: [PATCH v3 19/21] scsi: fnic: Switch to use %ptSp

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Wed, Nov 19, 2025 at 11:08:01AM +0100, Petr Mladek wrote:
> On Thu 2025-11-13 15:32:33, Andy Shevchenko wrote:
> > Use %ptSp instead of open coded variants to print content of
> > struct timespec64 in human readable format.
> 
> I was about to commit the changes into printk/linux.git and
> found a mistake during the final double check, see below.
> 
> > diff --git a/drivers/scsi/fnic/fnic_trace.c b/drivers/scsi/fnic/fnic_trace.c
> > index cdc6b12b1ec2..0a849a195a8e 100644
> > --- a/drivers/scsi/fnic/fnic_trace.c
> > +++ b/drivers/scsi/fnic/fnic_trace.c
> > @@ -215,30 +213,26 @@ int fnic_get_stats_data(struct stats_debug_info *debug,
> >  {
> >  	int len = 0;
> >  	int buf_size = debug->buf_size;
> > -	struct timespec64 val1, val2;
> > +	struct timespec64 val, val1, val2;
> >  	int i = 0;
> >  
> > -	ktime_get_real_ts64(&val1);
> > +	ktime_get_real_ts64(&val);
> >  	len = scnprintf(debug->debug_buffer + len, buf_size - len,
> >  		"------------------------------------------\n"
> >  		 "\t\tTime\n"
> >  		"------------------------------------------\n");
> >  
> > +	val1 = timespec64_sub(val, stats->stats_timestamps.last_reset_time);
> > +	val2 = timespec64_sub(val, stats->stats_timestamps.last_read_time);
> >  	len += scnprintf(debug->debug_buffer + len, buf_size - len,
> > -		"Current time :          [%lld:%ld]\n"
> > -		"Last stats reset time:  [%lld:%09ld]\n"
> > -		"Last stats read time:   [%lld:%ld]\n"
> > -		"delta since last reset: [%lld:%ld]\n"
> > -		"delta since last read:  [%lld:%ld]\n",
> > -	(s64)val1.tv_sec, val1.tv_nsec,
> > -	(s64)stats->stats_timestamps.last_reset_time.tv_sec,
> > -	stats->stats_timestamps.last_reset_time.tv_nsec,
> > -	(s64)stats->stats_timestamps.last_read_time.tv_sec,
> > -	stats->stats_timestamps.last_read_time.tv_nsec,
> > -	(s64)timespec64_sub(val1, stats->stats_timestamps.last_reset_time).tv_sec,
> > -	timespec64_sub(val1, stats->stats_timestamps.last_reset_time).tv_nsec,
> > -	(s64)timespec64_sub(val1, stats->stats_timestamps.last_read_time).tv_sec,
> > -	timespec64_sub(val1, stats->stats_timestamps.last_read_time).tv_nsec);
> > +			 "Current time :          [%ptSp]\n"
> > +			 "Last stats reset time:  [%ptSp]\n"
> > +			 "Last stats read time:   [%ptSp]\n"
> > +			 "delta since last reset: [%ptSp]\n"
> > +			 "delta since last read:  [%ptSp]\n",
> 
> Both delta times are printed at the end.
> 
> > +			 &val,
> > +			 &stats->stats_timestamps.last_reset_time, &val1,
> > +			 &stats->stats_timestamps.last_read_time, &val2);
> 
> I think that this should be:
> 
> 			 &stats->stats_timestamps.last_reset_time,
> 			 &stats->stats_timestamps.last_read_time,
> 			 &val1, &val2);
> 
> >  	stats->stats_timestamps.last_read_time = val1;
> 
> The original code stored the current time in "val1". This should be:
> 
> 	stats->stats_timestamps.last_read_time = val;
> 
> > @@ -416,8 +410,8 @@ int fnic_get_stats_data(struct stats_debug_info *debug,
> >  	jiffies_to_timespec64(stats->misc_stats.last_ack_time, &val2);
> 
> Just for record. Another values are stored into @val1 and @val2 at
> this point.
> 
> >  	len += scnprintf(debug->debug_buffer + len, buf_size - len,
> > -		  "Last ISR time: %llu (%8llu.%09lu)\n"
> > -		  "Last ACK time: %llu (%8llu.%09lu)\n"
> > +		  "Last ISR time: %llu (%ptSp)\n"
> > +		  "Last ACK time: %llu (%ptSp)\n"
> >  		  "Max ISR jiffies: %llu\n"
> >  		  "Max ISR time (ms) (0 denotes < 1 ms): %llu\n"
> >  		  "Corr. work done: %llu\n"
> > @@ -437,10 +431,8 @@ int fnic_get_stats_data(struct stats_debug_info *debug,
> >  		  "Number of rport not ready: %lld\n"
> >  		 "Number of receive frame errors: %lld\n"
> >  		 "Port speed (in Mbps): %lld\n",
> > -		  (u64)stats->misc_stats.last_isr_time,
> > -		  (s64)val1.tv_sec, val1.tv_nsec,
> > -		  (u64)stats->misc_stats.last_ack_time,
> > -		  (s64)val2.tv_sec, val2.tv_nsec,
> > +		  (u64)stats->misc_stats.last_isr_time, &val1,
> > +		  (u64)stats->misc_stats.last_ack_time, &val2,
> 
> So, this is correct!
> 
> >  		  (u64)atomic64_read(&stats->misc_stats.max_isr_jiffies),
> >  		  (u64)atomic64_read(&stats->misc_stats.max_isr_time_ms),
> >  		  (u64)atomic64_read(&stats->misc_stats.corr_work_done),
> 
> 
> Now, I think that there is no need to resend the entire huge patchset.
> 
> I could either fix this when comitting or commit the rest and
> you could send only this patch for review.

Thank you for the thoroughly done review, I changed that patch between the
versions and the problem is that for printf() specifiers (extensions) we do not
have an automatic type checking. We starve for a GCC plugin for that, yeah...

In any case, if you fold your changes in, I will appreciate that!
Otherwise it's also fine with me to send a patch separately later on.

> PS: All other patches look good. Well, nobody acked 7th patch yet.
>     But I think that the change is pretty straightforward and
>     we could do it even without an ack.

This is my understanding as well. It changes the output, but that output is
debug anyway. So I don't expect breakage of anything we have an obligation
to keep working.

-- 
With Best Regards,
Andy Shevchenko