Re: [PATCH v11 64/65] drm_print: fix drm_printer dynamic debug bypass

[jim . cromie]

On Fri, Mar 20, 2026 at 10:43 AM Louis Chauvet
<louis.chauvet@xxxxxxxxxxx> wrote:
>
> On Fri, 13 Mar 2026 07:20:29 -0600, Jim Cromie <jim.cromie@xxxxxxxxx> wrote:
> > [...]
> > mismatch in intel_pipe_config_compare(), the resulting UART storm
> > causes a hard timeout after 20 minutes (see below the snip).
> >
> > To fix this, change __drm_printfn_dbg() to use the explicit
> > drm_debug_enabled_instrumented() instead. This ensures the bit-test is
> > performed at runtime for this unguarded helper, stopping the UART storm.
>
> Why don't use use drm_debug_enabled directly? Does it make sense to call
> the _instrumented when [2] is not enabled?

my reason is so that we can turn on the pr-debug, and see how often
this happens.
If it happens a lot, we can look for ways to replace the bit-test with
a static-key guard.

That said, we could use drm_debug_enabled(), we'd lose the counting ability when
DRM_USE_DYNAMIC_DEBUG=n, but still have it for =y.
So Im happy with either way.

>
> >
>
> --
> Louis Chauvet <louis.chauvet@xxxxxxxxxxx>