Re: [PATCH] PCI/AER: update AER status string print to match other AER logs

[Tyler Baicar]

On 10/18/2017 6:14 AM, David Laight wrote:
> From: Tyler Baicar [mailto:tbaicar@xxxxxxxxxxxxxx]
> > Sent: 17 October 2017 18:14
> > On 10/17/2017 12:00 PM, David Laight wrote:
> > > From: Tyler Baicar
> > > > Sent: 17 October 2017 16:42
> > > > Currently the AER driver uses cper_print_bits() to print the AER status
> > > > string. This causes the status string to not include the proper PCI device
> > > > name prefix that the other AER prints include. Also, it has a different
> > > > print level than all the other AER prints.
> > > >
> > > > Update the AER driver to print the AER status string with the proper string
> > > > prefix and proper print level.
> > > >
> > > > Previous log example:
> > > >
> > > > e1000e 0003:01:00.1: aer_status: 0x00000041, aer_mask: 0x00000000
> > > > Receiver Error, Bad TLP
> > > ...
> > > > New log:
> > > >
> > > > e1000e 0003:01:00.1: aer_status: 0x00000041, aer_mask: 0x00000000
> > > > e1000e 0003:01:00.1: Receiver Error
> > > > e1000e 0003:01:00.1: Bad TLP
> > > Wouldn't it be better to manage to print the above all on 1 line?
>   
> > I broke them up into separate lines to simplify the code. If you look at
> > cper_print_bits(),
> > it is not a clean solution and involves some hard coded values to try to limit
> > the lines to 80 characters.
> I'm not sure the 80 char limit is needed.
>
>
> How about:
> #define MAX_STR 32
> void pr_bits(unsigned int val, const char *strs[], unsigned int num_str)
> {
>          const char *str[MAX_STR] = {};
>          unsigned int i, num;
>
>          if (num_str > MAX_STR)
>                  num_str = MAX_STR;
>          for (i = 0, num = 0; i < num_str; i++) {
>                  if (!(val & (1 << i)))
>                          continue;
>                  str[num++] = strs[i];
>          }
>          printf(" %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s %s\n" + (MAX_STR - num) * 3,
>                  str[0], str[1], str[2], str[3],
>                  str[4], str[5], str[6], str[7],
>                  str[8], str[9], str[10], str[11],
>                  str[12], str[13], str[14], str[15],
>                  str[16], str[17], str[18], str[19],
>                  str[20], str[21], str[22], str[23],
>                  str[24], str[25], str[26], str[27],
>                  str[28], str[29], str[30], str[31]);
> }
>
> For kernel use you'd probably want to pass in 'dev' and a printf list
> and use %pV to put the fixed text on the front of the line.
>
> All rather begging for a new %p? feature that is passed the value, strings
> and separator.
Hi David,

This seems like a bad approach. This can make the print in the kernel logs and 
the code both
look pretty awful. I would prefer to have each error that occurred have it's own 
print line in
the logs rather than introduce this code for the sole purpose of keeping the 
list on a single
print line. I don't see any real downside to having a few additional print lines 
in error
scenarios.

Thanks,
Tyler

--
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project.