drm: Refresh the explanation of debug categories

That comment wasn't super-readable, so I tried to improve it:

- Put the comment before the values it's documenting
- Add a mention to PRIME
- Reword things a bit to be a lighter read
- Add a note about the option to set the debug value at run-time

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Lespiau, Damien 2014-03-24 15:53:08 +00:00 committed by Dave Airlie
parent 90bde571ad
commit 1414b76c1e

View file

@ -88,41 +88,38 @@ struct videomode;
#include <drm/drm_hashtab.h>
#include <drm/drm_mm.h>
/*
* 4 debug categories are defined:
*
* CORE: Used in the generic drm code: drm_ioctl.c, drm_mm.c, drm_memory.c, ...
* This is the category used by the DRM_DEBUG() macro.
*
* DRIVER: Used in the vendor specific part of the driver: i915, radeon, ...
* This is the category used by the DRM_DEBUG_DRIVER() macro.
*
* KMS: used in the modesetting code.
* This is the category used by the DRM_DEBUG_KMS() macro.
*
* PRIME: used in the prime code.
* This is the category used by the DRM_DEBUG_PRIME() macro.
*
* Enabling verbose debug messages is done through the drm.debug parameter,
* each category being enabled by a bit.
*
* drm.debug=0x1 will enable CORE messages
* drm.debug=0x2 will enable DRIVER messages
* drm.debug=0x3 will enable CORE and DRIVER messages
* ...
* drm.debug=0xf will enable all messages
*
* An interesting feature is that it's possible to enable verbose logging at
* run-time by echoing the debug value in its sysfs node:
* # echo 0xf > /sys/module/drm/parameters/debug
*/
#define DRM_UT_CORE 0x01
#define DRM_UT_DRIVER 0x02
#define DRM_UT_KMS 0x04
#define DRM_UT_PRIME 0x08
/*
* Three debug levels are defined.
* drm_core, drm_driver, drm_kms
* drm_core level can be used in the generic drm code. For example:
* drm_ioctl, drm_mm, drm_memory
* The macro definition of DRM_DEBUG is used.
* DRM_DEBUG(fmt, args...)
* The debug info by using the DRM_DEBUG can be obtained by adding
* the boot option of "drm.debug=1".
*
* drm_driver level can be used in the specific drm driver. It is used
* to add the debug info related with the drm driver. For example:
* i915_drv, i915_dma, i915_gem, radeon_drv,
* The macro definition of DRM_DEBUG_DRIVER can be used.
* DRM_DEBUG_DRIVER(fmt, args...)
* The debug info by using the DRM_DEBUG_DRIVER can be obtained by
* adding the boot option of "drm.debug=0x02"
*
* drm_kms level can be used in the KMS code related with specific drm driver.
* It is used to add the debug info related with KMS mode. For example:
* the connector/crtc ,
* The macro definition of DRM_DEBUG_KMS can be used.
* DRM_DEBUG_KMS(fmt, args...)
* The debug info by using the DRM_DEBUG_KMS can be obtained by
* adding the boot option of "drm.debug=0x04"
*
* If we add the boot option of "drm.debug=0x06", we can get the debug info by
* using the DRM_DEBUG_KMS and DRM_DEBUG_DRIVER.
* If we add the boot option of "drm.debug=0x05", we can get the debug info by
* using the DRM_DEBUG_KMS and DRM_DEBUG.
*/
extern __printf(4, 5)
void drm_ut_debug_printk(unsigned int request_level,