[PATCH -next 0/4] Add LCLK control into Aspeed LPC sub drivers

[Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>]

Hi Zev,

On 11/2/2021 5:04 PM, Zev Weiss wrote:
> On Mon, Nov 01, 2021 at 04:36:38PM PDT, Joel Stanley wrote:
>> On Mon, 1 Nov 2021 at 23:18, <jae.hyun.yoo@intel.com> wrote:
>>>
>>> From: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
>>>
>>> Hello all,
>>>
>>> This series is for appliying below fix to all Aspped LPC sub drivers.
>>> https://lore.kernel.org/all/20201208091748.1920-1-wangzhiqiang.bj at bytedance.com/ 
>>>
>>>
>>> An LPC sub driver can be enabled without using the lpc-ctrl driver or it
>>> can be registered ahead of lpc-ctrl depends on each system 
>>> configuration and
>>> this difference introduces that LPC can be enabled without heart 
>>> beating of
>>> LCLK so it causes improper handling on host interrupts when the host 
>>> sends
>>> interrupts in that time frame. Then kernel eventually forcibly 
>>> disables the
>>> interrupt with dumping stack and printing a 'nobody cared this irq' 
>>> message
>>> out.
>>>
>>> To prevent this issue, all LPC sub drivers should enable LCLK 
>>> individually
>>> so this patch adds clock control logic into the remaining Aspeed LPC sub
>>> drivers.
>>
>> Thanks for sending this out!
>>
>> This will resolve a few of the issues we have in the issue tracker:
>>
>> https://github.com/openbmc/linux/issues/210
>> https://github.com/openbmc/linux/issues/130
>>
>> The patches look good to me. I think you've just missed Corey's PR for
>> v5.16, but I will stick them in the openbmc tree once they've had a
>> review.
>>
> 
> Hi Jae,
> 
> I tried this series out on the same in-progress OpenBMC port from issue 
> number 210 linked above and am still seeing problems (dmesg pasted below).
> 
> I cherry-picked commit f9241fe8b9652 ("ARM: dts: aspeed: Add uart 
> routing to device tree") from linux-next to allow the first patch to 
> apply cleanly; is there anything else I might be missing that'd be 
> needed to test the series properly?

Looks like below dmesg shows an error from 'aspeed_lpc_snoop_probe'
which this series doesn't touch. Do you have below fix in your code
tree?

https://lore.kernel.org/all/20201208091748.1920-1-wangzhiqiang.bj at bytedance.com/

Thanks,
Jae

> 
> Thanks,
> Zev
> 
> [??? 0.417811] irq 32: nobody cared (try booting with the "irqpoll" option)
> [??? 0.417858] CPU: 0 PID: 1 Comm: swapper Not tainted 
> 5.14.11-aee45db-dirty-4b119be-hacked #1
> [??? 0.417899] Hardware name: Generic DT based system
> [??? 0.417922] Backtrace: [??? 0.417958] [<807e64e4>] (dump_backtrace) 
> from [<807e6738>] (show_stack+0x20/0x24)
> [??? 0.418052]? r7:00000000 r6:00000008 r5:00000000 r4:80902b50
> [??? 0.418074] [<807e6718>] (show_stack) from [<807f09d0>] 
> (dump_stack+0x28/0x30)
> [??? 0.418133] [<807f09a8>] (dump_stack) from [<807e76c0>] 
> (__report_bad_irq+0x40/0xc0)
> [??? 0.418189]? r5:00000000 r4:80d43900
> [??? 0.418211] [<807e7680>] (__report_bad_irq) from [<80159c10>] 
> (note_interrupt+0x284/0x2dc)
> [??? 0.418286]? r9:80cbc000 r8:00000020 r7:00000000 r6:00000008 
> r5:00000000 r4:80d43900
> [??? 0.418307] [<8015998c>] (note_interrupt) from [<801569d4>] 
> (handle_irq_event+0xb4/0xc0)
> [??? 0.418366]? r10:00000000 r9:80cbc000 r8:80d439a8 r7:00000000 
> r6:00000008 r5:00000000
> [??? 0.418390]? r4:80d43900 r3:00000000
> [??? 0.418408] [<80156920>] (handle_irq_event) from [<8015acd0>] 
> (handle_level_irq+0xac/0x180)
> [??? 0.418464]? r5:00000000 r4:80d43900
> [??? 0.418484] [<8015ac24>] (handle_level_irq) from [<80155fa4>] 
> (handle_domain_irq+0x60/0x7c)
> [??? 0.418539]? r5:00000000 r4:80b8e7c8
> [??? 0.418558] [<80155f44>] (handle_domain_irq) from [<8010121c>] 
> (avic_handle_irq+0x64/0x6c)
> [??? 0.418618]? r7:80cbdc94 r6:ffffffff r5:80cbdc60 r4:80c02420
> [??? 0.418639] [<801011b8>] (avic_handle_irq) from [<80100aec>] 
> (__irq_svc+0x6c/0x90)
> [??? 0.418685] Exception stack(0x80cbdc60 to 0x80cbdca8)
> [??? 0.418722] dc60: 00000000 00000000 00000000 00000000 80d43900 
> 00000000 8529d180 00000020
> [??? 0.418756] dc80: 80d439a8 60000053 00000000 80cbdcdc 00000000 
> 80cbdcb0 8015a520 80157d4c
> [??? 0.418781] dca0: 40000053 ffffffff
> [??? 0.418807]? r5:40000053 r4:80157d4c
> [??? 0.418824] [<80157a0c>] (__setup_irq) from [<8015844c>] 
> (request_threaded_irq+0xe8/0x16c)
> [??? 0.418887]? r9:852acb60 r8:00000020 r7:80d43910 r6:80d43900 
> r5:00000000 r4:8529d180
> [??? 0.418908] [<80158364>] (request_threaded_irq) from [<8015bd80>] 
> (devm_request_threaded_irq+0x78/0xd0)
> [??? 0.418979]? r10:8092ed9c r9:00000000 r8:852acb60 r7:80d42410 
> r6:00000020 r5:8045ff98
> [??? 0.419004]? r4:8529d760 r3:00000080
> [??? 0.419021] [<8015bd08>] (devm_request_threaded_irq) from 
> [<8046049c>] (aspeed_lpc_snoop_probe+0x110/0x2e0)
> [??? 0.419116]? r10:80bab000 r9:80d42410 r8:8529d140 r7:00000000 
> r6:80d42400 r5:852acb60
> [??? 0.419138]? r4:00000000
> [??? 0.419155] [<8046038c>] (aspeed_lpc_snoop_probe) from [<804e6980>] 
> (platform_probe+0x54/0x9c)
> [??? 0.419237]? r9:80983b68 r8:00000000 r7:80d42410 r6:80b6f3dc 
> r5:80b6f3dc r4:80d42410
> [??? 0.419259] [<804e692c>] (platform_probe) from [<804e450c>] 
> (really_probe+0x1c4/0x46c)
> [??? 0.419309]? r5:00000000 r4:80d42410
> [??? 0.419329] [<804e4348>] (really_probe) from [<804e4888>] 
> (__driver_probe_device+0xd4/0x1bc)
> [??? 0.419381]? r7:80d42410 r6:80d42410 r5:80bcb44c r4:80b6f3dc
> [??? 0.419401] [<804e47b4>] (__driver_probe_device) from [<804e49b0>] 
> (driver_probe_device+0x40/0xd8)
> [??? 0.419460]? r9:80983b68 r8:00000000 r7:80d42410 r6:80b6f3dc r4:80bcb340
> [??? 0.419480] [<804e4970>] (driver_probe_device) from [<804e4d14>] 
> (__driver_attach+0xa4/0x1c8)
> [??? 0.419538]? r9:80983b68 r8:80a2c838 r7:80b71638 r6:80b6f3dc 
> r5:80d42454 r4:80d42410
> [??? 0.419556] [<804e4c70>] (__driver_attach) from [<804e2124>] 
> (bus_for_each_dev+0x84/0xd0)
> [??? 0.419608]? r7:80b71638 r6:804e4c70 r5:80b6f3dc r4:00000000
> [??? 0.419628] [<804e20a0>] (bus_for_each_dev) from [<804e5440>] 
> (driver_attach+0x28/0x30)
> [??? 0.419681]? r6:00000000 r5:852abd20 r4:80b6f3dc
> [??? 0.419700] [<804e5418>] (driver_attach) from [<804e2ac0>] 
> (bus_add_driver+0x114/0x200)
> [??? 0.419745] [<804e29ac>] (bus_add_driver) from [<804e5adc>] 
> (driver_register+0x98/0x128)
> [??? 0.419798]? r7:00000000 r6:00000007 r5:00000000 r4:80b6f3dc
> [??? 0.419818] [<804e5a44>] (driver_register) from [<804e7c2c>] 
> (__platform_driver_register+0x2c/0x34)
> [??? 0.419874]? r5:80c03e40 r4:80a1997c
> [??? 0.419890] [<804e7c00>] (__platform_driver_register) from 
> [<80a1999c>] (aspeed_lpc_snoop_driver_init+0x20/0x28)
> [??? 0.419951] [<80a1997c>] (aspeed_lpc_snoop_driver_init) from 
> [<80a01408>] (do_one_initcall+0x64/0x144)
> [??? 0.420024] [<80a013a4>] (do_one_initcall) from [<80a016e4>] 
> (kernel_init_freeable+0x198/0x218)
> [??? 0.420086]? r7:80a2c858 r6:00000007 r5:80c03e40 r4:80a4c8f0
> [??? 0.420108] [<80a0154c>] (kernel_init_freeable) from [<807f0c28>] 
> (kernel_init+0x20/0x134)
> [??? 0.420172]? r10:00000000 r9:00000000 r8:00000000 r7:00000000 
> r6:00000000 r5:807f0c08
> [??? 0.420194]? r4:00000000
> [??? 0.420211] [<807f0c08>] (kernel_init) from [<80100130>] 
> (ret_from_fork+0x14/0x24)
> [??? 0.420259] Exception stack(0x80cbdfb0 to 0x80cbdff8)
> [??? 0.420292] dfa0:???????????????????????????????????? 00000000 
> 00000000 00000000 00000000
> [??? 0.420326] dfc0: 00000000 00000000 00000000 00000000 00000000 
> 00000000 00000000 00000000
> [??? 0.420356] dfe0: 00000000 00000000 00000000 00000000 00000013 00000000
> [??? 0.420382]? r5:807f0c08 r4:00000000
> [??? 0.420400] handlers:
> [??? 0.420417] [<(ptrval)>] aspeed_lpc_snoop_irq
> [??? 0.420482] Disabling IRQ #32
> [??? 0.638932] Serial: 8250/16550 driver, 6 ports, IRQ sharing enabled
> [??? 0.643436] 1e787000.serial: ttyS5 at MMIO 0x1e787000 (irq = 32, 
> base_baud = 1546875) is a 8250
> [??? 0.645555] 1e784000.serial: ttyS4 at MMIO 0x1e784000 (irq = 31, 
> base_baud = 1500000) is a 16550A
> [??? 2.010064] Freeing initrd memory: 1072K
> [??? 2.232890] printk: console [ttyS4] enabled
> [??? 2.239349] timeriomem_rng 1e6e2078.hwrng: 32bits from 0x6961cb32 @ 1us
> [??? 2.262322] loop: module loaded
> [??? 2.284029] aspeed-smc 1e620000.spi: Using 100 MHz SPI frequency
> [??? 2.290471] aspeed-smc 1e620000.spi: mx66l51235f (65536 Kbytes)
> [??? 2.296451] aspeed-smc 1e620000.spi: CE0 window [ 0x20000000 - 
> 0x24000000 ] 64MB
> [??? 2.303977] aspeed-smc 1e620000.spi: CE1 window [ 0x24000000 - 
> 0x2a000000 ] 96MB
> [??? 2.311486] aspeed-smc 1e620000.spi: read control register: 203c0641
> [??? 2.542638] 5 fixed-partitions partitions found on MTD device bmc
> [??? 2.548875] Creating 5 MTD partitions on "bmc":
> [??? 2.553458] 0x000000000000-0x0000000e0000 : "u-boot"
> [??? 2.561247] 0x0000000e0000-0x000000100000 : "u-boot-env"
> [??? 2.569559] 0x000000100000-0x000000a00000 : "kernel"
> [??? 2.577301] 0x000000a00000-0x000002a00000 : "rofs"
> [??? 2.585054] 0x000002a00000-0x000004000000 : "rwfs"
> [??? 2.628232] libphy: Fixed MDIO Bus: probed
> [??? 2.634437] ftgmac100 1e660000.ethernet: Read MAC address 
> d0:50:99:f4:1e:18 from chip
> [??? 2.651029] libphy: ftgmac100_mdio: probed
> [??? 2.656253] RTL8211E Gigabit Ethernet 1e660000.ethernet--1:00: 
> attached PHY driver (mii_bus:phy_addr=1e660000.ethernet--1:00, irq=POLL)
> [??? 2.669669] ftgmac100 1e660000.ethernet eth0: irq 20, mapped at 1ecc0872
> [??? 2.680442] aspeed_vhub 1e6a0000.usb-vhub: Initialized virtual hub in 
> USB2 mode
> [??? 2.688464] Mass Storage Function, version: 2009/09/11
> [??? 2.693666] LUN: removable file: (no medium)
> [??? 2.698021] no file given for LUN0
> [??? 2.701605] g_mass_storage 1e6a0000.usb-vhub:p1: failed to start 
> g_mass_storage: -22
> [??? 2.710113] i2c /dev entries driver
> [??? 2.715459] aspeed-i2c-bus 1e78a040.i2c-bus: i2c bus 0 registered, 
> irq 33
> [??? 2.724045] aspeed-i2c-bus 1e78a080.i2c-bus: i2c bus 1 registered, 
> irq 34
> [??? 2.733972] aspeed-i2c-bus 1e78a0c0.i2c-bus: i2c bus 2 registered, 
> irq 35
> [??? 2.742252] aspeed-i2c-bus 1e78a100.i2c-bus: i2c bus 3 registered, 
> irq 36
> [??? 2.750599] aspeed-i2c-bus 1e78a140.i2c-bus: i2c bus 4 registered, 
> irq 37
> [??? 2.759769] aspeed-i2c-bus 1e78a180.i2c-bus: i2c bus 5 registered, 
> irq 38
> [??? 2.767994] aspeed-i2c-bus 1e78a1c0.i2c-bus: i2c bus 6 registered, 
> irq 39
> [??? 2.777783] at24 7-0050: 16384 byte 24c128 EEPROM, writable, 16 
> bytes/write
> [??? 2.785096] aspeed-i2c-bus 1e78a300.i2c-bus: i2c bus 7 registered, 
> irq 40
> [??? 2.793373] aspeed-i2c-bus 1e78a340.i2c-bus: i2c bus 8 registered, 
> irq 41
> [??? 2.801709] aspeed-i2c-bus 1e78a380.i2c-bus: i2c bus 9 registered, 
> irq 42
> [??? 2.814947] at24 14-0050: 2048 byte 24c16 EEPROM, read-only
> [??? 2.820929] i2c i2c-2: Added multiplexed i2c bus 14
> [??? 2.826513] i2c i2c-2: Added multiplexed i2c bus 15
> [??? 2.832192] i2c i2c-2: Added multiplexed i2c bus 16
> [??? 2.837821] i2c i2c-2: Added multiplexed i2c bus 17
> [??? 2.842944] pca954x 2-0070: registered 4 multiplexed busses for I2C 
> switch pca9545
> [??? 2.852110] i2c i2c-5: Added multiplexed i2c bus 18
> [??? 2.857847] i2c i2c-5: Added multiplexed i2c bus 19
> [??? 2.863603] i2c i2c-5: Added multiplexed i2c bus 20
> [??? 2.869410] i2c i2c-5: Added multiplexed i2c bus 21
> [??? 2.874378] pca954x 5-0073: registered 4 multiplexed busses for I2C 
> switch pca9545
> [??? 2.884631] Driver for 1-wire Dallas network protocol.
> [??? 3.009394] NET: Registered PF_INET6 protocol family
> [??? 3.017326] Segment Routing with IPv6
> [??? 3.021945] NET: Registered PF_PACKET protocol family
> [??? 3.027562] 8021q: 802.1Q VLAN Support v1.8
> [??? 3.263306] irq 32: nobody cared (try booting with the "irqpoll" option)
> [??? 3.270074] CPU: 0 PID: 5 Comm: kworker/u2:0 Not tainted 
> 5.14.11-aee45db-dirty-4b119be-hacked #1
> [??? 3.278889] Hardware name: Generic DT based system
> [??? 3.283699] Workqueue: events_unbound deferred_probe_work_func
> [??? 3.289601] Backtrace: [??? 3.292079] [<807e64e4>] (dump_backtrace) 
> from [<807e6738>] (show_stack+0x20/0x24)
> [??? 3.299716]? r7:00000000 r6:00000008 r5:00000000 r4:80902b50
> [??? 3.305382] [<807e6718>] (show_stack) from [<807f09d0>] 
> (dump_stack+0x28/0x30)
> [??? 3.312646] [<807f09a8>] (dump_stack) from [<807e76c0>] 
> (__report_bad_irq+0x40/0xc0)
> [??? 3.320433]? r5:00000000 r4:80d43900
> [??? 3.324022] [<807e7680>] (__report_bad_irq) from [<80159c10>] 
> (note_interrupt+0x284/0x2dc)
> [??? 3.332349]? r9:80cc6000 r8:00000020 r7:00000000 r6:00000008 
> r5:00000000 r4:80d43900
> [??? 3.340101] [<8015998c>] (note_interrupt) from [<801569d4>] 
> (handle_irq_event+0xb4/0xc0)
> [??? 3.348242]? r10:00000000 r9:80cc6000 r8:80d439a8 r7:00000000 
> r6:00000008 r5:00000000
> [??? 3.356077]? r4:80d43900 r3:00000400
> [??? 3.359660] [<80156920>] (handle_irq_event) from [<8015acd0>] 
> (handle_level_irq+0xac/0x180)
> [??? 3.368047]? r5:00000000 r4:80d43900
> [??? 3.371629] [<8015ac24>] (handle_level_irq) from [<80155fa4>] 
> (handle_domain_irq+0x60/0x7c)
> [??? 3.380024]? r5:00000000 r4:80b8e7c8
> [??? 3.383607] [<80155f44>] (handle_domain_irq) from [<8010121c>] 
> (avic_handle_irq+0x64/0x6c)
> [??? 3.391919]? r7:80cc7c84 r6:ffffffff r5:80cc7c50 r4:80c02420
> [??? 3.397586] [<801011b8>] (avic_handle_irq) from [<80100aec>] 
> (__irq_svc+0x6c/0x90)
> [??? 3.405187] Exception stack(0x80cc7c50 to 0x80cc7c98)
> [??? 3.410262] 7c40:???????????????????????????????????? 00000000 
> 00000000 00000000 00000000
> [??? 3.418458] 7c60: 80d43900 8529d180 85120d00 00000020 80d439a8 
> a0000013 00000000 80cc7ccc
> [??? 3.426647] 7c80: 00000400 80cc7ca0 8015a520 80157d4c 40000013 ffffffff
> [??? 3.433271]? r5:40000013 r4:80157d4c
> [??? 3.436854] [<80157a0c>] (__setup_irq) from [<8015844c>] 
> (request_threaded_irq+0xe8/0x16c)
> [??? 3.445171]? r9:8505fa20 r8:00000020 r7:80d43910 r6:80d43900 
> r5:00000000 r4:85120d00
> [??? 3.452922] [<80158364>] (request_threaded_irq) from [<8015bd80>] 
> (devm_request_threaded_irq+0x78/0xd0)
> [??? 3.462366]? r10:80d4ea20 r9:00000000 r8:8505fa20 r7:80d42c10 
> r6:00000020 r5:8044fd64
> [??? 3.470208]? r4:851208e0 r3:00000080
> [??? 3.473792] [<8015bd08>] (devm_request_threaded_irq) from 
> [<80450644>] (aspeed_kcs_probe+0x298/0x650)
> [??? 3.483072]? r10:8505fa54 r9:80833650 r8:ffffffea r7:80d42c10 
> r6:00000020 r5:8505fa20
> [??? 3.490912]? r4:80d42c00
> [??? 3.493456] [<804503ac>] (aspeed_kcs_probe) from [<804e6980>] 
> (platform_probe+0x54/0x9c)
> [??? 3.501617]? r10:8093c994 r9:80b9b840 r8:00000001 r7:80d42c10 
> r6:80b6e7b0 r5:80b6e7b0
> [??? 3.509458]? r4:80d42c10
> [??? 3.512003] [<804e692c>] (platform_probe) from [<804e450c>] 
> (really_probe+0x1c4/0x46c)
> [??? 3.519957]? r5:00000000 r4:80d42c10
> [??? 3.523538] [<804e4348>] (really_probe) from [<804e4888>] 
> (__driver_probe_device+0xd4/0x1bc)
> [??? 3.532017]? r7:80d42c10 r6:80d42c10 r5:80bcb44c r4:80b6e7b0
> [??? 3.537682] [<804e47b4>] (__driver_probe_device) from [<804e49b0>] 
> (driver_probe_device+0x40/0xd8)
> [??? 3.546683]? r9:80b9b840 r8:00000001 r7:80d42c10 r6:80cc7e84 r4:80bcb340
> [??? 3.553386] [<804e4970>] (driver_probe_device) from [<804e4be0>] 
> (__device_attach_driver+0xb8/0x148)
> [??? 3.562568]? r9:80b9b840 r8:00000000 r7:80d42c10 r6:80cc7e84 
> r5:80b6e7b0 r4:00000001
> [??? 3.570313] [<804e4b28>] (__device_attach_driver) from [<804e2648>] 
> (bus_for_each_drv+0x90/0xe0)
> [??? 3.579145]? r7:80b71484 r6:804e4b28 r5:80cc7e84 r4:00000000
> [??? 3.584812] [<804e25b8>] (bus_for_each_drv) from [<804e4f3c>] 
> (__device_attach+0x104/0x18c)
> [??? 3.593201]? r6:80d42c54 r5:00000001 r4:80d42c10
> [??? 3.597828] [<804e4e38>] (__device_attach) from [<804e536c>] 
> (device_initial_probe+0x1c/0x20)
> [??? 3.606390]? r6:80d42c10 r5:80b71638 r4:80d4ca50
> [??? 3.611019] [<804e5350>] (device_initial_probe) from [<804e2860>] 
> (bus_probe_device+0x94/0x9c)
> [??? 3.619662] [<804e27cc>] (bus_probe_device) from [<804e3f3c>] 
> (deferred_probe_work_func+0xa0/0xe8)
> [??? 3.628657]? r7:80b71484 r6:80b71470 r5:80d42c10 r4:80d4ca50
> [??? 3.634324] [<804e3e9c>] (deferred_probe_work_func) from [<801301ac>] 
> (process_one_work+0x1b4/0x46c)
> [??? 3.643506]? r10:80b71490 r9:00000000 r8:00000000 r7:80c85d00 
> r6:00000040 r5:80c045a0
> [??? 3.651342]? r4:80b7148c r3:804e3e9c
> [??? 3.654925] [<8012fff8>] (process_one_work) from [<8013066c>] 
> (worker_thread+0x208/0x528)
> [??? 3.663145]? r10:80c08a00 r9:00000088 r8:80b46840 r7:80c08a14 
> r6:80c045b4 r5:80c08a00
> [??? 3.670979]? r4:80c045a0
> [??? 3.673524] [<80130464>] (worker_thread) from [<80136f18>] 
> (kthread+0x138/0x160)
> [??? 3.680982]? r10:80c03860 r9:80cbde60 r8:80cc6000 r7:80c045a0 
> r6:80130464 r5:80c03840
> [??? 3.688822]? r4:80c02b80
> [??? 3.691369] [<80136de0>] (kthread) from [<80100130>] 
> (ret_from_fork+0x14/0x24)
> [??? 3.698633] Exception stack(0x80cc7fb0 to 0x80cc7ff8)
> [??? 3.703707] 7fa0:???????????????????????????????????? 00000000 
> 00000000 00000000 00000000
> [??? 3.711904] 7fc0: 00000000 00000000 00000000 00000000 00000000 
> 00000000 00000000 00000000
> [??? 3.720091] 7fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> [??? 3.726722]? r10:00000000 r9:00000000 r8:00000000 r7:00000000 
> r6:00000000 r5:80136de0
> [??? 3.734559]? r4:80c02b80 r3:00000000
> [??? 3.738142] handlers:
> [??? 3.740420] [<8337d287>] aspeed_lpc_snoop_irq
> [??? 3.744851] [<d8d6aeaf>] aspeed_kcs_irq
> [??? 3.748741] Disabling IRQ #32
> [??? 3.752597] ast-kcs-bmc 1e78902c.kcs: Initialised raw client for 
> channel 3
> [??? 3.760184] ast-kcs-bmc 1e78902c.kcs: Initialised IPMI client for 
> channel 3
> [??? 3.767235] ast-kcs-bmc 1e78902c.kcs: Initialised channel 3 at 0xca2
>