kernel/linux.git/drivers/gpu/drm/drm_print.c, branch v6.6.149

drm/printer: Allow NULL data in devcoredump printer

2024-10-10T09:57:36+00:00

[ Upstream commit 53369581dc0c68a5700ed51e1660f44c4b2bb524 ] We want to determine the size of the devcoredump before writing it out. To that end, we will run the devcoredump printer with NULL data to get the size, alloc data based on the generated offset, then run the devcorecump again with a valid data pointer to print. This necessitates not writing data to the data pointer on the initial pass, when it is NULL. v5: - Better commit message (Jonathan) - Add kerenl doc with examples (Jani) Cc: Maarten Lankhorst Acked-by: Maarten Lankhorst Signed-off-by: Matthew Brost Reviewed-by: Jonathan Cavitt Link: https://patchwork.freedesktop.org/patch/msgid/20240801154118.2547543-3-matthew.brost@intel.com Signed-off-by: Sasha Levin

drm_print: add _ddebug descriptor to drm_*dbg prototypes

2022-09-24T13:02:02+00:00

upgrade the callchain to drm_dbg() and drm_dev_dbg(); add a struct _ddebug ptr parameter to them, and supply that additional param by replacing the '_no_desc' flavor of dyndbg Factory macro currently used with the flavor that supplies the descriptor. NOTES: The descriptor gives these fns access to the decorator flags, but they do none of the dynamic-prefixing done by dynamic_emit_prefix(), which is currently static. DRM already has conventions for logging/messaging; just tossing optional decorations on top probably wouldn't help. Instead, existing flags (or new ones, perhaps 'sd' ala lspci) can be used to make current message conventions optional. This suggests a new drmdbg_prefix_emit() to handle prefixing locally. For CONFIG_DRM_USE_DYNAMIC_DEBUG=N, just pass null descriptor. desc->class_id is redundant with category parameter, but its availability is dependent on desc. Signed-off-by: Jim Cromie Link: https://lore.kernel.org/r/20220912052852.1123868-10-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman

drm_print: prefer bare printk KERN_DEBUG on generic fn

2022-09-24T13:02:02+00:00

drm_print.c calls pr_debug() just once, from __drm_printfn_debug(), which is a generic/service fn. The callsite is compile-time enabled by DEBUG in both DYNAMIC_DEBUG=y/n builds. For dyndbg builds, reverting this callsite back to bare printk is correcting a few anti-features: 1- callsite is generic, serves multiple drm users. it is soft-wired on currently by #define DEBUG could accidentally: #> echo -p > /proc/dynamic_debug/control 2- optional "decorations" by dyndbg are unhelpful/misleading here, they describe only the generic site, not end users IOW, 1,2 are unhelpful at best, and possibly confusing. reverting yields a nominal data and text shrink: text data bss dec hex filename 462583 36604 54592 553779 87333 /kernel/drivers/gpu/drm/drm.ko 462515 36532 54592 553639 872a7 -dirty/kernel/drivers/gpu/drm/drm.ko Signed-off-by: Jim Cromie Link: https://lore.kernel.org/r/20220912052852.1123868-9-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman

drm_print: optimize drm_debug_enabled for jump-label

2022-09-24T13:02:02+00:00

When CONFIG_DRM_USE_DYNAMIC_DEBUG=y, the drm.debug API (a macro stack, calling _+drm_*dbg() eventually) invokes a dyndbg Factory macro to create a descriptor for each callsite, thus making them individually >control-able. In this case, the calls to _drm_*dbg are unreachable unless the callsite is enabled. So those calls can short-circuit their early do-nothing returns. Provide and use __drm_debug_enabled(), to do this when config'd, or the _raw flags-check otherwize. And since dyndbg is in use, lets also instrument the remaining users of drm_debug_enabled, by wrapping the _raw in a macro with a: pr_debug("todo: is this frequent enough to optimize ?\n"); For CONFIG_DRM_USE_DYNAMIC_DEBUG=n, do no site instrumenting at all, since JUMP_LABEL might be off, and we don't want to make work. With drm, amdgpu, i915, nouveau loaded, heres remaining uses of drm_debug_enabled(), which costs ~1.5kb data to control the pr_debug("todo:..")s. Some of those uses might be ok to use __drm_debug_enabled() by inspection, others might warrant conversion to use dyndbg Factory macros, and that would want callrate data to estimate the savings possible. TBH, any remaining savings are probably small; drm.debug covers the vast bulk of the uses. Maybe "vblank" is the exception. :#> grep todo /proc/dynamic_debug/control | wc 21 168 2357 :#> grep todo /proc/dynamic_debug/control drivers/gpu/drm/drm_edid_load.c:178 [drm]edid_load =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/drm_vblank.c:410 [drm]drm_crtc_accurate_vblank_count =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/drm_vblank.c:787 [drm]drm_crtc_vblank_helper_get_vblank_timestamp_internal =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/drm_vblank.c:1491 [drm]drm_vblank_restore =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/drm_vblank.c:1433 [drm]drm_vblank_enable =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/drm_plane.c:2168 [drm]drm_mode_setplane =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/display/drm_dp_mst_topology.c:1359 [drm_display_helper]drm_dp_mst_wait_tx_reply =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/display/drm_dp_mst_topology.c:2864 [drm_display_helper]process_single_tx_qlock =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/display/drm_dp_mst_topology.c:2909 [drm_display_helper]drm_dp_queue_down_tx =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/display/drm_dp_mst_topology.c:1686 [drm_display_helper]drm_dp_mst_update_slots =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/i915/display/intel_dp.c:1111 [i915]intel_dp_print_rates =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/i915/display/intel_backlight.c:5434 [i915]cnp_enable_backlight =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/i915/display/intel_backlight.c:5459 [i915]intel_backlight_device_register =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/i915/display/intel_opregion.c:43 [i915]intel_opregion_notify_encoder =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/i915/display/intel_opregion.c:53 [i915]asle_set_backlight =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/i915/display/intel_bios.c:1088 [i915]intel_bios_is_dsi_present =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/i915/display/intel_display_debugfs.c:6153 [i915]i915_drrs_ctl_set =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/i915/intel_pcode.c:26 [i915]snb_pcode_read =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/i915/i915_getparam.c:785 [i915]i915_getparam_ioctl =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/amd/amdgpu/vcn_v2_5.c:282 [amdgpu]vcn_v2_5_process_interrupt =_ "todo: maybe avoid via dyndbg\n" drivers/gpu/drm/amd/amdgpu/vcn_v2_0.c:433 [amdgpu]vcn_v2_0_process_interrupt =_ "todo: maybe avoid via dyndbg\n" :#> Signed-off-by: Jim Cromie Link: https://lore.kernel.org/r/20220912052852.1123868-8-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman

drm_print: interpose drm_*dbg with forwarding macros

2022-09-24T13:02:01+00:00

change drm_dev_dbg & drm_dbg to macros, which forward to the renamed functions (with __ prefix added). Those functions sit below the categorized layer of macros implementing the DRM debug.category API, and implement most of it. These are good places to insert dynamic-debug jump-label mechanics, which will allow DRM to avoid the runtime cost of drm_debug_enabled(). no functional changes. memory cost baseline: (unchanged) bash-5.1# drms_load [ 9.220389] dyndbg: 1 debug prints in module drm [ 9.224426] ACPI: bus type drm_connector registered [ 9.302192] dyndbg: 2 debug prints in module ttm [ 9.305033] dyndbg: 8 debug prints in module video [ 9.627563] dyndbg: 127 debug prints in module i915 [ 9.721505] AMD-Vi: AMD IOMMUv2 functionality not available on this system - This is not a bug. [ 10.091345] dyndbg: 2196 debug prints in module amdgpu [ 10.106589] [drm] amdgpu kernel modesetting enabled. [ 10.107270] amdgpu: CRAT table not found [ 10.107926] amdgpu: Virtual CRAT table created for CPU [ 10.108398] amdgpu: Topology: Add CPU node [ 10.168507] dyndbg: 3 debug prints in module wmi [ 10.329587] dyndbg: 3 debug prints in module nouveau Signed-off-by: Jim Cromie Link: https://lore.kernel.org/r/20220912052852.1123868-4-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman

drm: POC drm on dyndbg - use in core, 2 helpers, 3 drivers.

2022-09-24T13:02:01+00:00

Use DECLARE_DYNDBG_CLASSMAP across DRM: - in .c files, since macro defines/initializes a record - in drivers, $mod_{drv,drm,param}.c ie where param setup is done, since a classmap is param related - in drm/drm_print.c since existing __drm_debug param is defined there, and we ifdef it, and provide an elaborated alternative. - in drm_*_helper modules: dp/drm_dp - 1st item in makefile target drivers/gpu/drm/drm_crtc_helper.c - random pick iirc. Since these modules all use identical CLASSMAP declarations (ie: names and .class_id's) they will all respond together to "class DRM_UT_*" query-commands: :#> echo class DRM_UT_KMS +p > /proc/dynamic_debug/control NOTES: This changes __drm_debug from int to ulong, so BIT() is usable on it. DRM's enum drm_debug_category values need to sync with the index of their respective class-names here. Then .class_id == category, and dyndbg's class FOO mechanisms will enable drm_dbg(DRM_UT_KMS, ...). Though DRM needs consistent categories across all modules, thats not generally needed; modules X and Y could define FOO differently (ie a different NAME => class_id mapping), changes are made according to each module's private class-map. No callsites are actually selected by this patch, since none are class'd yet. Signed-off-by: Jim Cromie Link: https://lore.kernel.org/r/20220912052852.1123868-3-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman

isystem: ship and use stdarg.h

2021-08-19T00:02:55+00:00

Ship minimal stdarg.h (1 type, 4 macros) as . stdarg.h is the only userspace header commonly used in the kernel. GPL 2 version of can be extracted from http://archive.debian.org/debian/pool/main/g/gcc-4.2/gcc-4.2_4.2.4.orig.tar.gz Signed-off-by: Alexey Dobriyan Acked-by: Rafael J. Wysocki Acked-by: Ard Biesheuvel Signed-off-by: Masahiro Yamada

drm/print: convert debug category macros into an enum

2019-11-14T12:08:57+00:00

Mostly for improved documentation, convert the debug category macros into an enum. Drop unused DRM_UT_NONE. Document previously undocumented categories. Reviewed-by: Joonas Lahtinen Acked-by: Ville Syrjälä Acked-by: Sean Paul Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/96582479e7829d92b89adb805f829e23043ca85c.1572258936.git.jani.nikula@intel.com

drm/print: underscore prefix functions that should be private to print

2019-11-14T12:08:42+00:00

We don't want people calling the functions directly. No functional changes. Reviewed-by: Rodrigo Vivi Acked-by: Ville Syrjälä Acked-by: Sean Paul Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/6b236ed4d2e6d2987eaaeb9cb737f9c3699281cc.1572258936.git.jani.nikula@intel.com

drm/print: rename drm_debug to __drm_debug to discourage use

2019-11-14T12:08:41+00:00

drm_debug_enabled() is the way to check. __drm_debug is now reserved for drm print code only. No functional changes. v2: Rebase on move unlikely() to drm_debug_enabled() Acked-by: Alex Deucher Reviewed-by: Eric Engestrom Acked-by: Ville Syrjälä Acked-by: Sean Paul Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/840ff7292d1a39512bac2fcb1f45de9d50694bf1.1572258936.git.jani.nikula@intel.com