The arm64 device running LTP hugetlb test suite caused test hang on stable-rc 5.5.5-rc1 due to [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow!. Same problem noticed while running libhugetlbfs test suite. Problematic patch not identified yet. hugemmap05.c:223: INFO: original nr_hugepages is 0 hugemmap05.c:236: INFO: original nr_overcommit_hugepages is 0 hugemmap05.c:104: INFO: check /proc/meminfo before allocation. hugemmap05.c:285: INFO: HugePages_Total is 192. hugemmap05.c:285: INFO: HugePages_Free is 192. hugemmap05.c:285: INFO: HugePages_Surp is 64. hugemmap05.c:285: INFO: HugePages_[ 51.411646] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! Rsvd is 192. [ 51.411735] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.419705] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.427680] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.434455] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.441179] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.447912] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.454639] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.461395] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.468175] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.475014] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.481868] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.488621] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.495367] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.502113] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.508845] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.515582] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.522316] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.529054] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.535836] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.542621] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.549399] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.556144] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.562897] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.569634] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.576378] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.583142] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.589889] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.596610] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! hugemmap05.c:260:[ 51.603356] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! INFO: First hex is 7070707 [ 51.610101] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 51.621956] [drm:ade_ldi_set_mode [kirin_drm]] *ERROR* failed to set pixel clk 0Hz (-22) hugemmap05.c:139: INFO: check /proc/meminfo. hugemmap05.c:285: INFO: HugePages_Total is 192. hugemmap05.c:285: INFO: HugePages_Free is 0. hugemmap05.c:285: INFO: HugePages_Surp is 64. hugemmap05.c:285: INFO: HugePages_Rsvd is 0. hugemmap05.c:163: PASS: hugepages overcommit test pass hugemmap05.c:180: INFO: restore nr_hugepages to 0. hugemmap05.c:189: INFO: restore nr_overcommit_hugepages to 0. Summary: passed 1 failed 0 skipped 0 warnings 0 tst_test.c:1217: INFO: Timeout per run is 0h 15m 00s mem.c:817: INFO: set nr_hugepages to 255 [ 54.139687] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 54.143384] [drm:ade_ldi_set_mode [kirin_drm]] *ERROR* failed to set pixel clk 0Hz (-22) [ 54.278589] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 54.280642] [drm:ade_ldi_set_mode [kirin_drm]] *ERROR* failed to set pixel clk 0Hz (-22) hugemmap06.c:139: PASS: No regression found. [ 54.520165] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 54.522769] [drm:ade_ldi_set_mode [kirin_drm]] *ERROR* failed to set pixel clk 0Hz (-22) [ 54.664774] [drm:ade_irq_handler [kirin_drm]] *ERROR* LDI underflow! [ 54.668013] [drm:ade_ldi_set_mode [kirin_drm]] *ERROR* failed to set pixel clk 0Hz (-22) <SYSTEM HANGS HERE> Ref: https://lkft.validation.linaro.org/scheduler/job/1227316#L4288 metadata: git branch: linux-5.5.y git repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git git commit: 7d6c8f2632c92635fcef4175921a7742f23947e4 git describe: v5.5.4-46-g7d6c8f2632c9 make_kernelversion: 5.5.5-rc1 kernel-config: http://snapshots.linaro.org/openembedded/lkft/lkft/sumo/hikey/lkft/linux-stable-rc-5.5/24/config build-location: http://snapshots.linaro.org/openembedded/lkft/lkft/sumo/hikey/lkft/linux-stable-rc-5.5/24 -- Linaro LKFT https://lkft.linaro.org