Greeting,

FYI, we noticed the following commit (built with gcc-9):

commit: b41be8ac8ed5d15c54fe14f64f8ab3658a242d3d ("[Intel-gfx] [PATCH v7 4/7] drm/i915: Add hw.pipe_mode to allow bigjoiner pipe/transcoder split")
url: https://github.com/0day-ci/linux/commits/Manasi-Navare/Final-prep-series-for-bigjoiner/20201106-063314
base: git://anongit.freedesktop.org/drm-intel for-linux-next

in testcase: ltp
version: ltp-x86_64-14c1f76-1_20201007
with following parameters:

	test: net_stress.broken_ip
	ucode: 0xdc

test-description: The LTP testsuite contains a collection of tools for testing the Linux kernel and related features.
test-url: http://linux-test-project.github.io/


on test machine: 4 threads Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz with 32G memory

caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):


If you fix the issue, kindly add following tag
Reported-by: kernel test robot <oliver.sang@intel.com>


[   20.371917] i915 0000:00:02.0: vgaarb: changed VGA decodes: olddecodes=io+mem,decodes=io+mem:owns=io+mem
 Journal to Pers
[   20.392241] i915 0000:00:02.0: [drm] Failed to load DMC firmware i915/skl_dmc_ver1_27.bin. Disabling runtime power management.
[   20.405025] i915 0000:00:02.0: [drm] DMC firmware homepage: https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/tree/i915
[   20.423642] CPU: 0 PID: 205 Comm: systemd-udevd Tainted: G          I       5.10.0-rc2-00419-gb41be8ac8ed5 #1
[   20.433574] Hardware name: Dell Inc. OptiPlex 7040/0Y7WYT, BIOS 1.1.1 10/07/2015
0m...
[   20.441024] RIP: 0010:skl_allocate_pipe_ddb+0x582/0xca0 [i915]
[   20.447442] Code: 89 ef e8 41 cb 0b 00 85 c0 0f 85 b7 fd ff ff 8b 5c 24 4c 8b 7c 24 44 31 d2 8b 74 24 3c 44 8b 5c 24 40 89 d8 0f af c7 44 89 d9 <f7> f6 31 d2 01 c1 8b 44 24 48 66 41 89 8e 2a 0a 00 00 0f b7 c9 01
[   20.466221] RSP: 0018:ffffc900003d3718 EFLAGS: 00010206
[   20.471450] RAX: 0000000000000000 RBX: 000000000000037c RCX: 0000000000000000
[   20.471450] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[   20.471450] RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
[   20.471451] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000003
[   20.471451] R13: ffff88886df3fea0 R14: ffff88886d3fd000 R15: ffff88886a4a0000
[   20.471452] FS:  00007f8812240d40(0000) GS:ffff888871c00000(0000) knlGS:0000000000000000
[   20.471453] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   20.471453] CR2: 00007f881223e127 CR3: 0000000870e1c001 CR4: 00000000003706f0
[   20.471454] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   20.471454] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   20.471455] Call Trace:
[   20.471459]  ? string+0x42/0x60
[   20.471521]  skl_compute_wm+0x494/0x800 [i915]
[   20.471524]  ? _cond_resched+0x19/0x40
1;39mHelper to s
[   20.568868]  drm_atomic_commit+0x13/0x60 [drm]
ynchronize boot 
[   20.574733]  intel_modeset_init_nogem+0x4f4/0xb00 [i915]
[   20.587499]  ? _cond_resched+0x19/0x40
[   20.591250]  ? mutex_lock+0x21/0x40
[0m.
[   20.594767]  i915_pci_probe+0x54/0x140 [i915]
[   20.599623]  local_pci_probe+0x42/0x80
[   20.603380]  ? _cond_resched+0x19/0x40
[   20.603382]  pci_device_probe+0x107/0x1c0
[   20.603385]  really_probe+0x1ca/0x420
[   20.603386]  driver_probe_device+0xe1/0x160
[   20.603388]  device_driver_attach+0x53/0x60
[   20.603389]  __driver_attach+0x8a/0x160
[   20.603390]  ? device_driver_attach+0x60/0x60
[   20.603391]  ? device_driver_attach+0x60/0x60
[   20.603392]  bus_for_each_dev+0x78/0xc0
[   20.603394]  bus_add_driver+0x14d/0x200
[   20.603395]  driver_register+0x6c/0xc0
[   20.603396]  ? 0xffffffffc0a90000
[   20.603431]  i915_init+0x5d/0x70 [i915]
[   20.603434]  do_one_initcall+0x44/0x200
[   20.603435]  ? _cond_resched+0x19/0x40
[   20.603437]  ? kmem_cache_alloc_trace+0x3c2/0x460
[   20.603439]  do_init_module+0x5c/0x220
[   20.603440]  load_module+0x1035/0x12a0
[   20.603441]  ? __kernel_read+0x14c/0x2e0
[   20.603444]  ? __do_sys_finit_module+0xb1/0x120
[   20.603444]  __do_sys_finit_module+0xb1/0x120
[   20.603446]  do_syscall_64+0x33/0x40
[   20.603448]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   20.603450] RIP: 0033:0x7f8812a2af59
[   20.603451] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 07 6f 0c 00 f7 d8 64 89 01 48
[   20.603452] RSP: 002b:00007ffdad2bda98 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[   20.603453] RAX: ffffffffffffffda RBX: 00005630118bb710 RCX: 00007f8812a2af59
[   20.603453] RDX: 0000000000000000 RSI: 00007f881292fcad RDI: 0000000000000015
[   20.603454] RBP: 00007f881292fcad R08: 0000000000000000 R09: 0000000000000000
[   20.603454] R10: 0000000000000015 R11: 0000000000000246 R12: 0000000000000000
[   20.603455] R13: 00005630118c2ce0 R14: 0000000000020000 R15: 00005630118bb710
[   20.603456] Modules linked in: acpi_cpufreq(-) coretemp kvm_intel i915(+) mei_wdt ahci libahci kvm intel_gtt irqbypass crct10dif_pclmul drm_kms_helper crc32_pclmul dell_wmi crc32c_intel dell_smbios wmi_bmof sparse_keymap ghash_clmulni_intel syscopyarea dell_wmi_descriptor sysfillrect rapl sysimgblt fb_sys_fops intel_cstate libata mei_me dcdbas drm mei intel_pch_thermal joydev wmi intel_uncore video intel_pmc_core acpi_pad ip_tables
[   20.603485] ---[ end trace 4443a7b5f5ecc864 ]---
[   20.603559] RIP: 0010:skl_allocate_pipe_ddb+0x582/0xca0 [i915]
[   20.603562] Code: 89 ef e8 41 cb 0b 00 85 c0 0f 85 b7 fd ff ff 8b 5c 24 4c 8b 7c 24 44 31 d2 8b 74 24 3c 44 8b 5c 24 40 89 d8 0f af c7 44 89 d9 <f7> f6 31 d2 01 c1 8b 44 24 48 66 41 89 8e 2a 0a 00 00 0f b7 c9 01
[   20.603562] RSP: 0018:ffffc900003d3718 EFLAGS: 00010206
[   20.603563] RAX: 0000000000000000 RBX: 000000000000037c RCX: 0000000000000000
[   20.603564] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[   20.603565] RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
[   20.603565] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000003
[   20.603565] R13: ffff88886df3fea0 R14: ffff88886d3fd000 R15: ffff88886a4a0000
[   20.603566] FS:  00007f8812240d40(0000) GS:ffff888871c00000(0000) knlGS:0000000000000000
[   20.603567] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   20.603567] CR2: 00007f881223e127 CR3: 0000000870e1c001 CR4: 00000000003706f0
[   20.603568] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   20.603568] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   20.603569] Kernel panic - not syncing: Fatal exception
[   20.603613] Kernel Offset: disabled
ACPI MEMORY or I/O RESET_REG.


To reproduce:

        git clone https://github.com/intel/lkp-tests.git
        cd lkp-tests
        bin/lkp install job.yaml  # job file is attached in this email
        bin/lkp run     job.yaml



Thanks,
Oliver Sang