Hi Imre, kernel test robot noticed the following build errors: [auto build test ERROR on drm-tip/drm-tip] url: https://github.com/intel-lab-lkp/linux/commits/Imre-Deak/drm-i915-dp-Fix-UHBR-link-M-N-values/20231114-043135 base: git://anongit.freedesktop.org/drm/drm-tip drm-tip patch link: https://lore.kernel.org/r/20231113201110.510724-4-imre.deak%40intel.com patch subject: [PATCH 4/4] drm/dp_mst: Fix PBN divider calculation for UHBR rates config: i386-randconfig-002-20231114 (https://download.01.org/0day-ci/archive/20231114/202311140621.sw31vG8M-lkp@xxxxxxxxx/config) compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231114/202311140621.sw31vG8M-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202311140621.sw31vG8M-lkp@xxxxxxxxx/ All errors (new ones prefixed by >>): ld: drivers/gpu/drm/display/drm_dp_mst_topology.o: in function `drm_dp_get_vc_payload_bw': >> drivers/gpu/drm/display/drm_dp_mst_topology.c:3598: undefined reference to `__udivdi3' vim +3598 drivers/gpu/drm/display/drm_dp_mst_topology.c 3570 3571 /** 3572 * drm_dp_get_vc_payload_bw - get the VC payload BW for an MST link 3573 * @mgr: The &drm_dp_mst_topology_mgr to use 3574 * @link_rate: link rate in 10kbits/s units 3575 * @link_lane_count: lane count 3576 * 3577 * Calculate the total bandwidth of a MultiStream Transport link. The returned 3578 * value is in units of PBNs/(timeslots/1 MTP). This value can be used to 3579 * convert the number of PBNs required for a given stream to the number of 3580 * timeslots this stream requires in each MTP. 3581 */ 3582 int drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr, 3583 int link_rate, int link_lane_count) 3584 { 3585 int ret; 3586 3587 if (link_rate == 0 || link_lane_count == 0) 3588 drm_dbg_kms(mgr->dev, "invalid link rate/lane count: (%d / %d)\n", 3589 link_rate, link_lane_count); 3590 3591 /* See DP v2.0 2.6.4.2, 2.7.6.3 VCPayload_Bandwidth_for_OneTimeSlotPer_MTP_Allocation */ 3592 /* 3593 * TODO: Return the value with a higher precision, allowing a better 3594 * slots per MTP allocation granularity. With the current returned 3595 * value +1 slot/MTP can get allocated on UHBR links. 3596 */ 3597 ret = mul_u32_u32(link_rate * link_lane_count, > 3598 drm_dp_bw_channel_coding_efficiency(drm_dp_is_uhbr_rate(link_rate))) / 3599 (1000000ULL * 8 * 5400); 3600 3601 return ret; 3602 } 3603 EXPORT_SYMBOL(drm_dp_get_vc_payload_bw); 3604 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
