2021-10-01 13:52:33

by Chris Murphy

[permalink] [raw]
Subject: 5.15.0-0.rc2: suspicious RCU usage

First seen with these kernels:
5.15.0-0.rc2.18.fc36.x86_64+debug
5.15.0-0.rc3.25.fc36.x86_64+debug

Did not see it with 5.14 series, but also didn't test any 5.15 kernel
prior to rc2.

There's actually two issues, not sure if they are related:

1.

[ 9.054169] =============================
[ 9.054170] WARNING: suspicious RCU usage
[ 9.054172] 5.15.0-0.rc3.25.fc36.x86_64+debug #1 Not tainted
[ 9.054173] -----------------------------
[ 9.054175] drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c:263
suspicious rcu_dereference_protected() usage!
[ 9.054178]
other info that might help us debug this:

[ 9.054180]
rcu_scheduler_active = 2, debug_locks = 1
[ 9.054182] 3 locks held by modprobe/670:
[ 9.054185] #0: ffffffffc0d160f0
(iwlwifi_opmode_table_mtx){+.+.}-{3:3}, at:
iwl_opmode_register+0x2c/0xe0 [iwlwifi]
[ 9.054209] #1: ffffffffa21ee910 (rtnl_mutex){+.+.}-{3:3}, at:
iwl_op_mode_mvm_start+0xa41/0xce0 [iwlmvm]
[ 9.054239] #2: ffff9f6586cc3608 (&mvm->mutex){+.+.}-{3:3}, at:
iwl_op_mode_mvm_start+0xa4d/0xce0 [iwlmvm]
[ 9.054260]
stack backtrace:
[ 9.054261] CPU: 7 PID: 670 Comm: modprobe Not tainted
5.15.0-0.rc3.25.fc36.x86_64+debug #1
[ 9.054264] Hardware name: LENOVO 20QDS3E200/20QDS3E200, BIOS
N2HET63W (1.46 ) 06/01/2021
[ 9.054265] Call Trace:
[ 9.054268] dump_stack_lvl+0x57/0x72
[ 9.054273] iwl_mvm_init_fw_regd+0x110/0x170 [iwlmvm]
[ 9.054292] iwl_mvm_init_mcc+0x42/0x1b0 [iwlmvm]
[ 9.054308] iwl_op_mode_mvm_start+0xc8e/0xce0 [iwlmvm]
[ 9.054332] _iwl_op_mode_start.isra.0+0x3f/0x80 [iwlwifi]
[ 9.054349] iwl_opmode_register+0x6f/0xe0 [iwlwifi]
[ 9.054363] ? 0xffffffffc0be0000
[ 9.054367] iwl_mvm_init+0x36/0x1000 [iwlmvm]
[ 9.054383] do_one_initcall+0x64/0x320
[ 9.054389] ? rcu_read_lock_sched_held+0x3f/0x80
[ 9.054393] ? trace_kmalloc+0x38/0xe0
[ 9.054396] ? kmem_cache_alloc_trace+0x17c/0x280
[ 9.054405] do_init_module+0x5c/0x270
[ 9.054409] __do_sys_init_module+0x130/0x190
[ 9.054427] do_syscall_64+0x38/0x90
[ 9.054433] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 9.054437] RIP: 0033:0x7ff05073b97e
[ 9.054441] Code: 48 8b 0d ad 74 0e 00 f7 d8 64 89 01 48 83 c8 ff
c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 af 00 00
00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 7a 74 0e 00 f7 d8 64 89
01 48
[ 9.054444] RSP: 002b:00007ffce3da9378 EFLAGS: 00000246 ORIG_RAX:
00000000000000af
[ 9.054448] RAX: ffffffffffffffda RBX: 00005645f1041db0 RCX: 00007ff05073b97e
[ 9.054450] RDX: 00005645ef77ba2a RSI: 00000000000fb6e6 RDI: 00005645f1ad0180
[ 9.054452] RBP: 00005645f1ad0180 R08: 00005645f1044cc0 R09: 00000000000fa010
[ 9.054454] R10: 0000000000000005 R11: 0000000000000246 R12: 00005645ef77ba2a
[ 9.054456] R13: 00005645f1041ec0 R14: 00005645f1041db0 R15: 00005645f1044dd0
[ 9.061824] ------------[ cut here ]------------
[ 9.061829] WARNING: CPU: 5 PID: 670 at net/wireless/reg.c:3107
reg_process_self_managed_hint+0x198/0x1e0 [cfg80211]
[ 9.061883] Modules linked in: snd_soc_core(+) kvm_intel(+)
pcc_cpufreq(-) iTCO_wdt(+) snd_compress intel_pmc_bxt ac97_bus
snd_pcm_dmaengine iTCO_vendor_support mei_hdcp mei_wdt snd_hda_intel
kvm intel_rapl_msr snd_intel_dspcfg snd_intel_sdw_acpi snd_hda_codec
irqbypass iwlmvm(+) snd_hda_core rapl snd_hwdep intel_cstate snd_seq
mac80211 snd_seq_device intel_uncore snd_pcm uvcvideo think_lmi(+)
libarc4 firmware_attributes_class intel_wmi_thunderbolt wmi_bmof
videobuf2_vmalloc btusb i2c_i801 videobuf2_memops snd_timer
videobuf2_v4l2 videobuf2_common i2c_smbus thunderbolt btrtl btbcm
iwlwifi videodev btintel mei_me processor_thermal_device_pci_legacy
processor_thermal_device bluetooth joydev mc processor_thermal_rfim
mei cfg80211 thinkpad_acpi ucsi_acpi processor_thermal_mbox idma64
ledtrig_audio ecdh_generic typec_ucsi processor_thermal_rapl
platform_profile intel_rapl_common typec intel_pch_thermal
intel_soc_dts_iosf rfkill snd int3403_thermal soundcore
int340x_thermal_zone acpi_pad
[ 9.062083] acpi_tad int3400_thermal acpi_thermal_rel zram
ip_tables i915 hid_multitouch crct10dif_pclmul i2c_algo_bit
crc32_pclmul crc32c_intel ttm drm_kms_helper ghash_clmulni_intel cec
serio_raw e1000e drm nvme nvme_core i2c_hid_acpi i2c_hid wmi video
pinctrl_cannonlake fuse
[ 9.062158] CPU: 5 PID: 670 Comm: modprobe Not tainted
5.15.0-0.rc3.25.fc36.x86_64+debug #1
[ 9.062164] Hardware name: LENOVO 20QDS3E200/20QDS3E200, BIOS
N2HET63W (1.46 ) 06/01/2021
[ 9.062168] RIP: 0010:reg_process_self_managed_hint+0x198/0x1e0 [cfg80211]
[ 9.062211] Code: 0e 01 03 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41
5f 5d c3 49 8d 7c 24 70 be ff ff ff ff e8 50 f1 35 e0 85 c0 0f 85 b8
fe ff ff <0f> 0b e9 b1 fe ff ff 0f 0b 80 3d 47 bf 0b 00 00 0f 85 94 fe
ff ff
[ 9.062214] RSP: 0018:ffffc353c141bc50 EFLAGS: 00010246
[ 9.062219] RAX: 0000000000000000 RBX: ffff9f6586cc3568 RCX: 0000000000000001
[ 9.062223] RDX: 0000000000000002 RSI: ffff9f6586cc0650 RDI: ffff9f658701c410
[ 9.062225] RBP: ffffc353c141bcc8 R08: 0000000000000000 R09: 0000000000000001
[ 9.062228] R10: ffffffffa372c720 R11: 0000000000000000 R12: ffff9f6586cc05e0
[ 9.062231] R13: ffff9f6586cc3568 R14: ffffc353c141bd30 R15: ffff9f6586cc3560
[ 9.062236] FS: 00007ff050624740(0000) GS:ffff9f68ee400000(0000)
knlGS:0000000000000000
[ 9.062239] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9.062242] CR2: 00005572b3a19440 CR3: 00000001029ca006 CR4: 00000000003706e0
[ 9.062246] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9.062249] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9.062252] Call Trace:
[ 9.062258] ? kfree+0x319/0x4c0
[ 9.062282] regulatory_set_wiphy_regd_sync+0x31/0x90 [cfg80211]
[ 9.062321] iwl_mvm_init_mcc+0xa9/0x1b0 [iwlmvm]
[ 9.062352] iwl_op_mode_mvm_start+0xc8e/0xce0 [iwlmvm]
[ 9.062384] _iwl_op_mode_start.isra.0+0x3f/0x80 [iwlwifi]
[ 9.062404] iwl_opmode_register+0x6f/0xe0 [iwlwifi]
[ 9.062416] ? 0xffffffffc0be0000
[ 9.062423] iwl_mvm_init+0x36/0x1000 [iwlmvm]
[ 9.062438] do_one_initcall+0x64/0x320
[ 9.062445] ? rcu_read_lock_sched_held+0x3f/0x80
[ 9.062450] ? trace_kmalloc+0x38/0xe0
[ 9.062455] ? kmem_cache_alloc_trace+0x17c/0x280
[ 9.062464] do_init_module+0x5c/0x270
[ 9.062471] __do_sys_init_module+0x130/0x190
[ 9.062496] do_syscall_64+0x38/0x90
[ 9.062504] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 9.062509] RIP: 0033:0x7ff05073b97e
[ 9.062514] Code: 48 8b 0d ad 74 0e 00 f7 d8 64 89 01 48 83 c8 ff
c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 af 00 00
00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 7a 74 0e 00 f7 d8 64 89
01 48
[ 9.062517] RSP: 002b:00007ffce3da9378 EFLAGS: 00000246 ORIG_RAX:
00000000000000af
[ 9.062523] RAX: ffffffffffffffda RBX: 00005645f1041db0 RCX: 00007ff05073b97e
[ 9.062526] RDX: 00005645ef77ba2a RSI: 00000000000fb6e6 RDI: 00005645f1ad0180
[ 9.062529] RBP: 00005645f1ad0180 R08: 00005645f1044cc0 R09: 00000000000fa010
[ 9.062554] R10: 0000000000000005 R11: 0000000000000246 R12: 00005645ef77ba2a
[ 9.062557] R13: 00005645f1041ec0 R14: 00005645f1041db0 R15: 00005645f1044dd0
[ 9.062580] irq event stamp: 149273
[ 9.062583] hardirqs last enabled at (149281):
[<ffffffffa0e00e42>] asm_sysvec_call_function+0x12/0x20
[ 9.062588] hardirqs last disabled at (149288):
[<ffffffffa01727a5>] __up_console_sem+0x45/0x70
[ 9.062594] softirqs last enabled at (149246):
[<ffffffffa00ec798>] __irq_exit_rcu+0xd8/0x110
[ 9.062599] softirqs last disabled at (149237):
[<ffffffffa00ec798>] __irq_exit_rcu+0xd8/0x110
[ 9.062603] ---[ end trace fec5843beb08d839 ]---


2. these appear in red text

[ 23.150258] iwlwifi 0000:00:14.3: Unhandled alg: 0xc0400707
[ 23.150380] iwlwifi 0000:00:14.3: Unhandled alg: 0xc0400707


Downstream bug report has the full dmesg attached
https://bugzilla.redhat.com/show_bug.cgi?id=2009750



--
Chris Murphy


2021-10-01 13:57:18

by Chris Murphy

[permalink] [raw]
Subject: Re: 5.15.0-0.rc2: suspicious RCU usage

[ 8.481619] iwlwifi 0000:00:14.3: loaded firmware version
46.6b541b68.0 9000-pu-b0-jf-b0-46.ucode op_mode iwlmvm
[ 8.919971] iwlwifi 0000:00:14.3: Detected Intel(R) Wireless-AC
9560 160MHz, REV=0x318

linux-firmware-20210818-122.fc35.noarch

NOTE: it's a rawhide/36 kernel with Fedora 35 user space, but at the
moment 35 and 36 have the same firmware version.
--
Chris Murphy

2021-11-23 02:40:24

by Chris Murphy

[permalink] [raw]
Subject: Re: 5.15.0-0.rc2: suspicious RCU usage

This is still a problem with 5.16.0-0.rc2.18.fc36.x86_64+debug

Downstream bug
https://bugzilla.redhat.com/show_bug.cgi?id=2009750
Full dmesg
https://bugzilla.redhat.com/attachment.cgi?id=1843093


[ 10.086769] iwlwifi 0000:00:14.3: Detected Intel(R) Wireless-AC
9560 160MHz, REV=0x318
[ 10.103027] zram0: detected capacity change from 0 to 16777216
[ 10.106045] thermal thermal_zone6: failed to read out thermal zone (-61)
[ 10.178076] iwlwifi 0000:00:14.3: base HW address: c8:e2:65:04:99:cb
[ 10.205970] snd_hda_intel 0000:00:1f.3: DSP detected with PCI
class/subclass/prog-if info 0x040380
[ 10.229278] snd_hda_intel 0000:00:1f.3: Digital mics found on
Skylake+ platform, using SOF driver

[ 10.233993] =============================
[ 10.233996] WARNING: suspicious RCU usage
[ 10.233999] 5.16.0-0.rc2.18.fc36.x86_64+debug #1 Not tainted
[ 10.234002] -----------------------------
[ 10.234004] drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c:264
suspicious rcu_dereference_protected() usage!
[ 10.234008]
other info that might help us debug this:

[ 10.234010]
rcu_scheduler_active = 2, debug_locks = 1
[ 10.234013] 3 locks held by modprobe/671:
[ 10.234017] #0: ffffffffc0b2d0f0
(iwlwifi_opmode_table_mtx){+.+.}-{3:3}, at:
iwl_opmode_register+0x2c/0xe0 [iwlwifi]
[ 10.234055] #1: ffffffffa040dc10 (rtnl_mutex){+.+.}-{3:3}, at:
iwl_op_mode_mvm_start+0xa49/0xcf0 [iwlmvm]
[ 10.234096] #2: ffff9344c9f1b688 (&mvm->mutex){+.+.}-{3:3}, at:
iwl_op_mode_mvm_start+0xa55/0xcf0 [iwlmvm]
[ 10.234127]
stack backtrace:
[ 10.234130] CPU: 3 PID: 671 Comm: modprobe Not tainted
5.16.0-0.rc2.18.fc36.x86_64+debug #1
[ 10.234134] Hardware name: LENOVO 20QDS3E200/20QDS3E200, BIOS
N2HET64W (1.47 ) 07/19/2021
[ 10.234137] Call Trace:
[ 10.234140] <TASK>
[ 10.234144] dump_stack_lvl+0x59/0x73
[ 10.234153] iwl_mvm_init_fw_regd+0x110/0x170 [iwlmvm]
[ 10.234179] iwl_mvm_init_mcc+0x42/0x1b0 [iwlmvm]
[ 10.234202] iwl_op_mode_mvm_start+0xc94/0xcf0 [iwlmvm]
[ 10.234239] _iwl_op_mode_start.isra.0+0x3f/0x80 [iwlwifi]
[ 10.234265] iwl_opmode_register+0x6f/0xe0 [iwlwifi]
[ 10.234287] ? 0xffffffffc07df000
[ 10.234294] iwl_mvm_init+0x36/0x1000 [iwlmvm]
[ 10.234316] do_one_initcall+0x64/0x350
[ 10.234323] ? rcu_read_lock_sched_held+0x3f/0x70
[ 10.234329] ? trace_kmalloc+0x38/0x100
[ 10.234333] ? kmem_cache_alloc_trace+0x1ee/0x3a0
[ 10.234345] do_init_module+0x5c/0x280
[ 10.234352] __do_sys_init_module+0x130/0x190
[ 10.234382] do_syscall_64+0x38/0x90
[ 10.234389] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 10.234394] RIP: 0033:0x7f761e21799e
[ 10.234399] Code: 48 8b 0d 8d 74 0e 00 f7 d8 64 89 01 48 83 c8 ff
c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 af 00 00
00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 5a 74 0e 00 f7 d8 64 89
01 48
[ 10.234402] RSP: 002b:00007fff30183428 EFLAGS: 00000246 ORIG_RAX:
00000000000000af
[ 10.234408] RAX: ffffffffffffffda RBX: 000056233a3dbdb0 RCX: 00007f761e21799e
[ 10.234411] RDX: 0000562338eeaa2a RSI: 00000000000fc6ee RDI: 000056233ae71200
[ 10.234413] RBP: 000056233ae71200 R08: 000056233a3ded20 R09: 00000000000fc010
[ 10.234416] R10: 0000000000000005 R11: 0000000000000246 R12: 0000562338eeaa2a
[ 10.234419] R13: 000056233a3dbec0 R14: 000056233a3dbdb0 R15: 000056233a3dee30
[ 10.234445] </TASK>
[ 10.238914] ------------[ cut here ]------------
[ 10.239002] WARNING: CPU: 4 PID: 671 at net/wireless/reg.c:3107
reg_process_self_managed_hint+0x198/0x1e0 [cfg80211]
[ 10.239060] Modules linked in: snd_hda_intel kvm(+)
snd_intel_dspcfg snd_intel_sdw_acpi irqbypass snd_hda_codec
snd_hda_core rapl iwlmvm(+) snd_hwdep intel_cstate intel_uncore
snd_seq snd_seq_device mac80211 snd_pcm think_lmi(+) btusb wmi_bmof
firmware_attributes_class intel_wmi_thunderbolt libarc4 uvcvideo btrtl
videobuf2_vmalloc btbcm videobuf2_memops snd_timer btintel
videobuf2_v4l2 i2c_i801 processor_thermal_device_pci_legacy
videobuf2_common i2c_smbus bluetooth processor_thermal_device iwlwifi
thunderbolt videodev processor_thermal_rfim mei_me
processor_thermal_mbox joydev mc mei idma64 ecdh_generic cfg80211
processor_thermal_rapl intel_rapl_common thinkpad_acpi
intel_soc_dts_iosf intel_pch_thermal ledtrig_audio platform_profile
rfkill snd int3403_thermal soundcore int340x_thermal_zone
int3400_thermal acpi_pad acpi_thermal_rel acpi_tad zram ip_tables
hid_multitouch i915 crct10dif_pclmul crc32_pclmul crc32c_intel
ghash_clmulni_intel e1000e nvme serio_raw nvme_core ucsi_acpi ttm
[ 10.239244] typec_ucsi typec i2c_hid_acpi i2c_hid wmi video
pinctrl_cannonlake ipmi_devintf ipmi_msghandler fuse
[ 10.239270] CPU: 4 PID: 671 Comm: modprobe Not tainted
5.16.0-0.rc2.18.fc36.x86_64+debug #1
[ 10.239275] Hardware name: LENOVO 20QDS3E200/20QDS3E200, BIOS
N2HET64W (1.47 ) 07/19/2021
[ 10.239278] RIP: 0010:reg_process_self_managed_hint+0x198/0x1e0 [cfg80211]
[ 10.239341] Code: de 09 03 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41
5f 5d c3 49 8d 7c 24 70 be ff ff ff ff e8 80 33 5f de 85 c0 0f 85 b8
fe ff ff <0f> 0b e9 b1 fe ff ff 0f 0b 80 3d b7 be 0b 00 00 0f 85 94 fe
ff ff
[ 10.239344] RSP: 0018:ffffab090191bc50 EFLAGS: 00010246
[ 10.239350] RAX: 0000000000000000 RBX: ffff9344c9f1b5e8 RCX: 0000000000000001
[ 10.239354] RDX: 0000000000000002 RSI: ffffffff9f809f4d RDI: ffffffff9f8a878e
[ 10.239357] RBP: ffffab090191bcc8 R08: 000000026248c01c R09: 0000000000000000
[ 10.239360] R10: 0000000000000001 R11: 0000000000000000 R12: ffff9344c9f18640
[ 10.239363] R13: ffff9344c9f1b5e8 R14: ffffab090191bd30 R15: ffff9344c9f1b5e0
[ 10.239366] FS: 00007f761e100740(0000) GS:ffff93482da00000(0000)
knlGS:0000000000000000
[ 10.239370] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 10.239373] CR2: 00007f9b3bc6eed0 CR3: 000000010b688004 CR4: 00000000003706e0
[ 10.239376] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 10.239379] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 10.239382] Call Trace:
[ 10.239386] <TASK>
[ 10.239389] ? rcu_read_lock_sched_held+0x3f/0x70
[ 10.239413] regulatory_set_wiphy_regd_sync+0x31/0x90 [cfg80211]
[ 10.239462] iwl_mvm_init_mcc+0xa9/0x1b0 [iwlmvm]
[ 10.239494] iwl_op_mode_mvm_start+0xc94/0xcf0 [iwlmvm]
[ 10.239534] _iwl_op_mode_start.isra.0+0x3f/0x80 [iwlwifi]
[ 10.239560] iwl_opmode_register+0x6f/0xe0 [iwlwifi]
[ 10.239582] ? 0xffffffffc07df000
[ 10.239619] iwl_mvm_init+0x36/0x1000 [iwlmvm]
[ 10.239643] do_one_initcall+0x64/0x350
[ 10.239649] ? rcu_read_lock_sched_held+0x3f/0x70
[ 10.239654] ? trace_kmalloc+0x38/0x100
[ 10.239659] ? kmem_cache_alloc_trace+0x1ee/0x3a0
[ 10.239671] do_init_module+0x5c/0x280
[ 10.239679] __do_sys_init_module+0x130/0x190
[ 10.239709] do_syscall_64+0x38/0x90
[ 10.239717] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 10.239721] RIP: 0033:0x7f761e21799e
[ 10.239726] Code: 48 8b 0d 8d 74 0e 00 f7 d8 64 89 01 48 83 c8 ff
c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 af 00 00
00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 5a 74 0e 00 f7 d8 64 89
01 48
[ 10.239730] RSP: 002b:00007fff30183428 EFLAGS: 00000246 ORIG_RAX:
00000000000000af
[ 10.239736] RAX: ffffffffffffffda RBX: 000056233a3dbdb0 RCX: 00007f761e21799e
[ 10.239739] RDX: 0000562338eeaa2a RSI: 00000000000fc6ee RDI: 000056233ae71200
[ 10.239742] RBP: 000056233ae71200 R08: 000056233a3ded20 R09: 00000000000fc010
[ 10.239745] R10: 0000000000000005 R11: 0000000000000246 R12: 0000562338eeaa2a
[ 10.239748] R13: 000056233a3dbec0 R14: 000056233a3dbdb0 R15: 000056233a3dee30
[ 10.239774] </TASK>
[ 10.239777] irq event stamp: 157423
[ 10.239780] hardirqs last enabled at (157429):
[<ffffffff9e178e10>] __up_console_sem+0x60/0x70
[ 10.239785] hardirqs last disabled at (157434):
[<ffffffff9e178df5>] __up_console_sem+0x45/0x70
[ 10.239789] softirqs last enabled at (156456):
[<ffffffff9e0f25b7>] __irq_exit_rcu+0x107/0x170
[ 10.239794] softirqs last disabled at (156427):
[<ffffffff9e0f25b7>] __irq_exit_rcu+0x107/0x170
[ 10.239798] ---[ end trace 3d5bcc984dacd264 ]---
[ 10.252933] ieee80211 phy0: Selected rate control algorithm 'iwl-mvm-rs'