[PATCH v11 11/19] drm_print: wrap drm_dev_dbg in _dynamic_func_call_no_desc

Jim Cromie
2022-01-07T05:30:23Z

make drm_dev_dbg() macro CONFIG_DRM_USE_DYNAMIC_DEBUG dependent:

=N direct forwarding: drm_dev_dbg -> __drm_dev_dbg()
=Y wrap __drm_dev_dbg in _dynamic_func_call_no_desc().

This adds the metadata which creates a /proc/dynamic_debug/control
entry for each callsite, and exposes it for selective enablement.

NB: include header in header so wrapper is available

proof of function:

bash-5.1# grep 'ring test' /proc/dynamic_debug/control
drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c:453 [amdgpu]amdgpu_ring_test_helper =xf "ring test on %s succeeded\012"

less
452 else
453 DRM_DEV_DEBUG(adev->dev, "ring test on %s succeeded\n",
454 ring->name);
drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c lines 417-454/458 byte 12536/12575 100% (press RETURN)

new prdbg callsite counts:
bash-5.1# drms_load
[ 20.533990] dyndbg: 1 debug prints in module drm
[ 20.535637] ACPI: bus type drm_connector registered
[ 20.624951] dyndbg: 2 debug prints in module ttm
[ 20.627853] dyndbg: 8 debug prints in module video
[ 20.922442] dyndbg: 127 debug prints in module i915
[ 20.984159] AMD-Vi: AMD IOMMUv2 functionality not available on this system - This is not a bug.
[ 21.310216] dyndbg: 2196 debug prints in module amdgpu
[ 21.324537] [drm] amdgpu kernel modesetting enabled.
[ 21.325092] amdgpu: CRAT table not found
[ 21.325512] amdgpu: Virtual CRAT table created for CPU
[ 21.326009] amdgpu: Topology: Add CPU node
[ 21.401137] dyndbg: 3 debug prints in module wmi
[ 21.532540] dyndbg: 3 debug prints in module nouveau

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
include/drm/drm_print.h | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h
index f8fa5af11310..1eef315a0a65 100644
--- a/include/drm/drm_print.h
+++ b/include/drm/drm_print.h
@@ -383,8 +383,14 @@ void __drm_dev_dbg(const struct device *dev, enum drm_debug_category category,
} \
})

+#if !defined(CONFIG_DRM_USE_DYNAMIC_DEBUG)
#define drm_dev_dbg(dev, eCat, fmt, ...) \
__drm_dev_dbg(dev, eCat, fmt, ##__VA_ARGS__)
+#else
+#define drm_dev_dbg(dev, eCat, fmt, ...) \
+ _dynamic_func_call_no_desc(fmt, __drm_dev_dbg, \
+ dev, eCat, fmt, ##__VA_ARGS__)
+#endif

/**
* DRM_DEV_DEBUG() - Debug output for generic drm code
--
2.33.1