On 6/11/20 1:52 PM, Daniel Thompson wrote:

On Wed, Jun 10, 2020 at 11:42:43PM -0700, Joe Perches wrote:

quoted

On Thu, 2020-06-11 at 08:26 +0200, Greg Kroah-Hartman wrote:

quoted

On Wed, Jun 10, 2020 at 01:23:56PM -0700, Joe Perches wrote:

quoted

On Wed, 2020-06-10 at 12:49 -0700, Joe Perches wrote:

quoted

On Wed, 2020-06-10 at 15:37 +0200, Greg Kroah-Hartman wrote:

quoted

Please work with the infrastructure we have, we have spent a lot of time
and effort to make it uniform to make it easier for users and
developers.

Not quite.

This lack of debug grouping by type has been a
_long_ standing issue with drivers.

quoted

Don't regress and try to make driver-specific ways of doing
things, that way lies madness...

It's not driver specific, it allows driver developers to
better isolate various debug states instead of keeping
lists of specific debug messages and enabling them
individually.

For instance, look at the homebrew content in
drivers/gpu/drm/drm_print.c that does _not_ use
dynamic_debug.

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"
"\t\tBit 2 (0x04)  will enable KMS messages (modesetting code)\n"
"\t\tBit 3 (0x08)  will enable PRIME messages (prime code)\n"
"\t\tBit 4 (0x10)  will enable ATOMIC messages (atomic code)\n"
"\t\tBit 5 (0x20)  will enable VBL messages (vblank code)\n"
"\t\tBit 7 (0x80)  will enable LEASE messages (leasing code)\n"
"\t\tBit 8 (0x100) will enable DP messages (displayport code)");
module_param_named(debug, __drm_debug, int, 0600);

void drm_dev_dbg(const struct device *dev, enum drm_debug_category category,
		 const char *format, ...)
{
	struct va_format vaf;
	va_list args;

	if (!drm_debug_enabled(category))
		return;

Ok, and will this proposal be able to handle stuff like this?

Yes, that's the entire point.

Currently I think there not enough "levels" to map something like
drm.debug to the new dyn dbg feature. I don't think it is intrinsic
but I couldn't find the bit of the code where the 5-bit level in struct
_ddebug is converted from a mask to a bit number and vice-versa.

Here [1] is Joe's initial suggestion. But I decided that bitmask is a
good start for the discussion.

I guess we can add new member uint "level" in struct _ddebug so that we
can cover more "levels" (types, groups).

-- 
regards,
Stan

[1] https://lkml.org/lkml/2020/5/21/915