Re: [PATCH v2 1/7] media: uvcvideo: Use pr_cont() macro

[Joe Perches]

On Thu, 2020-11-05 at 10:50 +0100, Ricardo Ribalda wrote:
> Hi Joe

Rehi Ricardo.
 
> On Thu, Nov 5, 2020 at 12:59 AM Joe Perches <joe@xxxxxxxxxxx> wrote:
> > It looks as if all the pr_cont uses in the code are odd and repetitive.
> > 
> > Perhaps it'd be sensible to add something like:
> 
> Looks like a great idea. Queued for my v3
> 
> https://github.com/ribalda/linux/commit/1623b648331d7f69c8a9f6b199e119f6c8ee61c6
> 
> I let Laurent decide if we should squash with the previous patch or not.
> 
> Thanks!
> 
> > 
> > #define uvc_trace_cont(flag, fmt, ...)                                  \
> > do {                                                                    \
> >         if (uvc_trace_param & (flag))                                   \
> >                 pr_cont(fmt, ##__VA_ARGS__);                            \
> > } while (0)
> > 
> > and change all the uses like:
> > 
> > -               if (uvc_trace_param & UVC_TRACE_PROBE)
> > -                       printk(KERN_CONT " <- SU %d", entity->id);
> > +               uvc_trace_cont(UVC_TRACE_PROBE, " <- SU %d", entity->id);
> > 

While I know the only uses of uvc_trace_cont are with UVC_TRACE_PROBE,
there are other existing uvc_trace(flag, ...) uses.

I think the uvc_trace_cont mechanism should require a flag and not
assume UVC_TRACE_PROBE so it's possible, even though currently unused,
for other uvc_trace calls to be continued.

$ git grep -Poh '\buvc_trace\(\w+' drivers/media | sort | uniq -c
      1 uvc_trace(flag
      6 uvc_trace(UVC_TRACE_CALLS
      1 uvc_trace(UVC_TRACE_CAPTURE
      2 uvc_trace(UVC_TRACE_CLOCK
     15 uvc_trace(UVC_TRACE_CONTROL
     42 uvc_trace(UVC_TRACE_DESCR
      6 uvc_trace(UVC_TRACE_FORMAT
     12 uvc_trace(UVC_TRACE_FRAME
      7 uvc_trace(UVC_TRACE_PROBE
      1 uvc_trace(UVC_TRACE_STATS
      6 uvc_trace(UVC_TRACE_STATUS
      4 uvc_trace(UVC_TRACE_SUSPEND
      6 uvc_trace(UVC_TRACE_VIDEO