Re: [PATCH v6 39/57] dyndbg/drm: POC add tracebits sysfs-knob

From: Daniel Vetter
Date: Wed Sep 07 2022 - 03:00:06 EST


On Sun, Sep 04, 2022 at 03:41:16PM -0600, Jim Cromie wrote:
> clone DRM.debug interface to DRM.tracebits: ie map bits to
> drm-debug-categories, except this interface enables messages to
> tracefs, not to syslog.
>
> 1- we reuse the class-map added previously.
> this reflects the single source of both syslog/trace events
>
> 2- add a 2nd struct ddebug_classes_bitmap_param
> refs 1, reusing it.
> flags = "T", to enable trace-events on this callsite.
>
> 3- module_param_cb([2]) - does the sysfs part
>
> Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>

All the drm patches (excluding nouveau) I haven't commented on:

Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>

I think nouveau I'll leave up to nouveau folks.
-Daniel



> ---
> drivers/gpu/drm/drm_print.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c
> index c50edbf443d3..75d0cecd7e86 100644
> --- a/drivers/gpu/drm/drm_print.c
> +++ b/drivers/gpu/drm/drm_print.c
> @@ -45,6 +45,9 @@
> unsigned long __drm_debug;
> EXPORT_SYMBOL(__drm_debug);
>
> +unsigned long __drm_trace;
> +EXPORT_SYMBOL(__drm_trace);
> +
> MODULE_PARM_DESC(debug, "Enable debug output, where each bit enables a debug category.\n"
> "\t\tBit 0 (0x01) will enable CORE messages (drm core code)\n"
> "\t\tBit 1 (0x02) will enable DRIVER messages (drm controller code)\n"
> @@ -77,6 +80,13 @@ static struct ddebug_class_param drm_debug_bitmap = {
> .map = &drm_debug_classes,
> };
> module_param_cb(debug, &param_ops_dyndbg_classes, &drm_debug_bitmap, 0600);
> +
> +static struct ddebug_class_param drm_trace_bitmap = {
> + .bits = &__drm_trace,
> + .flags = "T",
> + .map = &drm_debug_classes,
> +};
> +module_param_cb(tracecats, &param_ops_dyndbg_classes, &drm_trace_bitmap, 0600);
> #endif
>
> void __drm_puts_coredump(struct drm_printer *p, const char *str)
> --
> 2.37.2
>

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch