> -----Original Message----- > From: Murthy, Arun R <[email protected]> > Sent: Monday, September 21, 2026 6:38 PM > To: [email protected] > Cc: [email protected]; [email protected]; Jani > Nikula > <[email protected]>; Ville Syrjälä <[email protected]>; > Nautiyal, Ankit K <[email protected]>; G M, Adarsh > <[email protected]>; Murthy, Arun R <[email protected]> > Subject: [PATCH libdrm 2/2] tests/crtclist: add utility to inspect CRTC usage > > Add a small diagnostic utility built on the new drmModeGetCrtcList() API. It > prints the total number of CRTCs, how many are free vs in use, and a per-CRTC > line with state, scanout framebuffer and active mode. > > Built like the other tests/ utilities (drmdevice, modeprint); it is a > human-facing > tool and is intentionally not registered as a meson test, since correctness is > covered by the drmmode_crtc_list_ult suite. > ULT is removed from this patch, as this utility itself should suffice. This paragraph will be removed in the next version.
Thanks and Regards, Arun R Murthy ------------------- > Signed-off-by: Arun R Murthy <[email protected]> > --- > tests/crtclist.c | 116 > ++++++++++++++++++++++++++++++++++++++++++++++ > tests/meson.build | 9 ++++ > 2 files changed, 125 insertions(+) > create mode 100644 tests/crtclist.c > > diff --git a/tests/crtclist.c b/tests/crtclist.c new file mode 100644 index > 00000000..7ac16853 > --- /dev/null > +++ b/tests/crtclist.c > @@ -0,0 +1,116 @@ > +/* > + * Copyright © 2026 Intel Corporation > + * > + * Permission is hereby granted, free of charge, to any person > +obtaining a copy > + * of this software and associated documentation files (the > +"Software"), to deal > + * in the Software without restriction, including without limitation > +the rights > + * to use, copy, modify, merge, publish, distribute, sublicense, and/or > +sell > + * copies of the Software, and to permit persons to whom the Software > +is > + * furnished to do so, subject to the following conditions: > + * > + * The above copyright notice and this permission notice shall be > +included in > + * all copies or substantial portions of the Software. > + * > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, > +EXPRESS OR > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF > +MERCHANTABILITY, > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO > EVENT > +SHALL THE > + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES > OR > +OTHER > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, > +ARISING FROM, > + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER > +DEALINGS IN THE > + * SOFTWARE. > + */ > + > +/* > + * crtclist - inspect CRTC usage on a DRM device via drmModeGetCrtcList(). > + * > + * Prints the total number of CRTCs, how many are free vs in use, and a > + * per-CRTC line showing state, scanout framebuffer and active mode. > +Useful > + * for compositor bring-up to see which CRTCs are available. > + * > + * Usage: crtclist [/dev/dri/cardN] (defaults to the first KMS node) > + */ > + > +#include <fcntl.h> > +#include <stdio.h> > +#include <unistd.h> > + > +#include <xf86drm.h> > +#include <xf86drmMode.h> > + > +static int open_kms_node(void) > +{ > + char path[64]; > + int i; > + > + for (i = 0; i < 16; i++) { > + int fd; > + > + snprintf(path, sizeof(path), "/dev/dri/card%d", i); > + fd = open(path, O_RDWR | O_CLOEXEC); > + if (fd < 0) > + continue; > + if (drmIsKMS(fd)) { > + printf("Using %s\n", path); > + return fd; > + } > + close(fd); > + } > + return -1; > +} > + > +int main(int argc, char **argv) > +{ > + drmModeCrtcListPtr list; > + int fd, i; > + > + if (argc > 1) > + fd = open(argv[1], O_RDWR | O_CLOEXEC); > + else > + fd = open_kms_node(); > + > + if (fd < 0) { > + fprintf(stderr, "No accessible KMS DRM device (try running as > root).\n"); > + return 1; > + } > + > + list = drmModeGetCrtcList(fd); > + if (!list) { > + fprintf(stderr, "drmModeGetCrtcList() failed\n"); > + close(fd); > + return 1; > + } > + > + printf("Total CRTCs : %d\n", list->count); > + printf("Available : %d\n", list->count_available); > + printf("In use : %d\n\n", list->count - list->count_available); > + > + printf("%-5s %-8s %-13s %-8s %s\n", > + "idx", "crtc_id", "state", "fb_id", "mode"); > + printf("-------------------------------------------------------\n"); > + for (i = 0; i < list->count; i++) { > + drmModeCrtcInfoPtr c = &list->crtcs[i]; > + const char *state; > + > + if (c->in_use) > + state = "IN USE"; > + else if (c->driver_active) > + state = "ACTIVE"; > + else > + state = "FREE"; > + > + printf("%-5d %-8u %-13s %-8u ", > + c->index, c->crtc_id, state, c->buffer_id); > + if (c->in_use) > + printf("%ux%u @ %uHz (%s)\n", > + c->width, c->height, c->mode.vrefresh, > + c->mode.name); > + else if (c->driver_active) > + printf("(active in hardware, not enabled via KMS)\n"); > + else > + printf("-\n"); > + } > + > + drmModeFreeCrtcList(list); > + close(fd); > + return 0; > +} > diff --git a/tests/meson.build b/tests/meson.build index ac9e66b0..9c98bc2b > 100644 > --- a/tests/meson.build > +++ b/tests/meson.build > @@ -69,6 +69,15 @@ drmdevice = executable( > install : with_install_tests, > ) > > +crtclist = executable( > + 'crtclist', > + files('crtclist.c'), > + include_directories : [inc_root, inc_drm], > + link_with : libdrm, > + c_args : libdrm_c_args, > + install : with_install_tests, > +) > + > test('hash', hash) > test('drmsl', drmsl) > test('drmdevice', drmdevice) > -- > 2.25.1
