From: Tvrtko Ursulin tvrtko.ursulin@intel.com
This series tries to solve a few issues in the current DRM logging code to primarily make it clearer which messages belong to which driver.
Main problem is that currently some logging functions allow individual drivers to override the log prefix (since they are defined as macros, or static inlines), while other hardcode the "drm" prefix into them due being situated in the DRM core modules.
Another thing is that I noticed the DRM_NAME macro which is used for this is defined in the uAPI header and had a comment which looked outdated.
Therefore I introduce a new define, called, DRM_LOG_NAME, this time defined internally in the kernel headers and not exported in the uAPI.
I also refactored some logging functions to take this string as a parameter instead of hardcoding it.
Individual drivers can then override this define to make DRM logging functions prefix their message with the respective driver prefix.
End result in the case of the i915 driver looks like this:
Old log:
[drm] Found 128MB of eDRAM [drm:skl_enable_dc6 [i915]] Enabling DC6
New log:
[i915] Found 128MB of eDRAM [i915:skl_enable_dc6 [i915]] Enabling DC6
There is some redundancy in the debug logs, as can be seen in the line above, but this comes from drm_printk printing the calling function name using the %ps formatting specifier and __builtin_return_address. Theoretically we could remove the driver prefix from debug messages, but that would make the messages a bit unusually formatted like:
[skl_enable_dc6 [i915]] Enabling DC6
Better would probably be:
[i915:skl_enable_dc6] Enabling DC6
But I do not know how to achieve that apart from changing the drm_printk wrapper macros to pass in __func__ and drop the __builtin_return_address business. And that would also mean all DRM drivers would have to start defining DRM_LOG_NAME or would lose the module owner info. So I opted not to go that route for now.
Main question is whether people find all this an interesting change or would prefer to leave the logging prefixes as they were, or perhaps do some heavier changes to DRM logging.
Cc: dri-devel@lists.freedesktop.org
Tvrtko Ursulin (6): drm/armada: Simplify drm_dev_init error log drm: Introduce unexported DRM_LOG_NAME define for logging drm/i915: Give our log messages our name drm: Respect driver set DRM_LOG_NAME in drm_printk drm: Respect driver set DRM_LOG_NAME in drm_dev_printk drm: Respect driver set DRM_LOG_NAME in drm_info_printer
drivers/gpu/drm/armada/armada_drv.c | 3 +- drivers/gpu/drm/drm_print.c | 20 ++++++------ drivers/gpu/drm/i915/i915_drv.c | 2 +- drivers/gpu/drm/i915/i915_drv.h | 5 +++ drivers/gpu/drm/i915/intel_display.c | 3 +- include/drm/drm_print.h | 61 +++++++++++++++++++++--------------- include/uapi/drm/drm.h | 2 +- 7 files changed, 55 insertions(+), 41 deletions(-)