serial console problem with kernel 3.18.0-rc4

DISCUSSION Helge Deller 4 participants 8 messages Nov 11, 2014 – Jan 2, 2015 TTY layer and serial drivers

lore

Share & tools

lore

Helge Deller

author

2014-11-11 19:13 UTC #0 lore raw

While testing kernel 3.18-rc4 I'm facing a problem with serial console.

I'm seeing at bootup this message:

[   17.724000] console [ttyS0] disabled

after that it's just hanging.

It seems as if ttyS0 is somehow being reprogrammed which then disturbs the serial ports on the receiver side (in my case a HP PCI Diva Serial [GSP] Multiport UART). Any idea what changed between 3.17 and 3.18 which have caused this behavior ? Full log below.

Helge

serial driver: drivers/tty/serial/8250/8250_pci.c

PCI info:
00:04.1 Serial controller: Hewlett-Packard Company Diva Serial [GSP] Multiport UART (rev 03) (prog-if 02 [16550])
Subsystem: Hewlett-Packard Company Device 1283
Flags: medium devsel, IRQ 70
Memory at ffffffff80000000 (32-bit, non-prefetchable) [size=4K]
I/O ports at 0040 [size=64]
Capabilities: [48] Power Management version 2
Kernel driver in use: serial

dmesg after bootup:

[   17.708000] Serial: 8250/16550 driver, 8 ports, IRQ sharing enabled
[   17.724000] serial 0000:00:04.1: enabling device (0142 -> 0143)
[   17.724000] console [ttyS0] disabled
[   17.880000] serial 0000:00:04.1: ttyS0 at MMIO 0xffffffff80000000 (irq = 70, base_baud = 115200) is a 16550A
[   17.996000] console [ttyS0] enabled
[   38.888000] INFO: rcu_sched detected stalls on CPUs/tasks: { 3} (detected by 1, t=5252 jiffies, g=-290, c=-291, q=2)
[   38.888000] Task dump for CPU 3:
[   38.888000] swapper/0       R  running task        0     1      0 0x00000004
[   38.888000] Backtrace:
[   38.888000]  [<0000000040200848>] vprintk_emit+0x570/0x5f8
[   38.888000]  [<0000000040200bdc>] printk+0x64/0x78
[   38.888000]  [<0000000040201fc0>] register_console+0x438/0x550
[   38.888000]  [<0000000040688bb8>] uart_add_one_port+0x400/0x5d0
[   38.888000]  [<000000004068e6d4>] serial8250_register_8250_port+0x3e4/0x448
[   38.888000]  [<0000000040695f44>] pciserial_init_ports+0x22c/0x2c8
[   38.888000]  [<0000000040696628>] pciserial_init_one+0x250/0x2e0
[   38.888000]  [<00000000405f3880>] pci_device_probe+0xb0/0x150
[   38.888000]  [<00000000406a8244>] driver_probe_device+0x204/0x570
[   38.888000]  [<00000000406a8728>] __driver_attach+0xe0/0x158
[   38.888000]  [<00000000406a4558>] bus_for_each_dev+0xd0/0x128
[   38.888000]  [<00000000406a76f8>] driver_attach+0x48/0x60
[   38.888000]  [<00000000406a6de8>] bus_add_driver+0x268/0x460
[   38.888000]  [<00000000406a915c>] driver_register+0x124/0x1d0
[   38.888000]  [<00000000405f336c>] __pci_register_driver+0x64/0x78
[   38.888000]  [<00000000401375e4>] serial_pci_driver_init+0x44/0x58

[   59.084000] timer_interrupt(CPU 3): delayed! cycles 85EBC4C7D rem 2BAF83  next/now 2765C08677/276594D6F4
[   59.140000] bootconsole [ttyB0] disabled
[   59.144000] serial 0000:00:04.1: ttyS1 at MMIO 0xffffffff80000008 (irq = 70, base_baud = 115200) is a 16450
[   59.164000] serial 0000:00:04.1: ttyS2 at MMIO 0xffffffff80000010 (irq = 70, base_baud = 115200) is a 16550A

James Bottomley

2015-01-01 01:33 UTC #1 lore raw

Quoted 53 lines · Helge Deller

While testing kernel 3.18-rc4 I'm facing a problem with serial console.
I'm seeing at bootup this message:
[   17.724000] console [ttyS0] disabled
after that it's just hanging.
It seems as if ttyS0 is somehow being reprogrammed which then disturbs the serial ports on the receiver side (in my case a HP PCI Diva Serial [GSP] Multiport UART). Any idea what changed between 3.17 and 3.18 which have caused this behavior ? Full log below.
Helge
serial driver: drivers/tty/serial/8250/8250_pci.c
PCI info:
00:04.1 Serial controller: Hewlett-Packard Company Diva Serial [GSP] Multiport UART (rev 03) (prog-if 02 [16550])
Subsystem: Hewlett-Packard Company Device 1283
Flags: medium devsel, IRQ 70
Memory at ffffffff80000000 (32-bit, non-prefetchable) [size=4K]
I/O ports at 0040 [size=64]
Capabilities: [48] Power Management version 2
Kernel driver in use: serial
dmesg after bootup:
[   17.708000] Serial: 8250/16550 driver, 8 ports, IRQ sharing enabled
[   17.724000] serial 0000:00:04.1: enabling device (0142 -> 0143)
[   17.724000] console [ttyS0] disabled
[   17.880000] serial 0000:00:04.1: ttyS0 at MMIO 0xffffffff80000000 (irq = 70, base_baud = 115200) is a 16550A
[   17.996000] console [ttyS0] enabled
[   38.888000] INFO: rcu_sched detected stalls on CPUs/tasks: { 3} (detected by 1, t=5252 jiffies, g=-290, c=-291, q=2)
[   38.888000] Task dump for CPU 3:
[   38.888000] swapper/0       R  running task        0     1      0 0x00000004
[   38.888000] Backtrace:
[   38.888000]  [<0000000040200848>] vprintk_emit+0x570/0x5f8
[   38.888000]  [<0000000040200bdc>] printk+0x64/0x78
[   38.888000]  [<0000000040201fc0>] register_console+0x438/0x550
[   38.888000]  [<0000000040688bb8>] uart_add_one_port+0x400/0x5d0
[   38.888000]  [<000000004068e6d4>] serial8250_register_8250_port+0x3e4/0x448
[   38.888000]  [<0000000040695f44>] pciserial_init_ports+0x22c/0x2c8
[   38.888000]  [<0000000040696628>] pciserial_init_one+0x250/0x2e0
[   38.888000]  [<00000000405f3880>] pci_device_probe+0xb0/0x150
[   38.888000]  [<00000000406a8244>] driver_probe_device+0x204/0x570
[   38.888000]  [<00000000406a8728>] __driver_attach+0xe0/0x158
[   38.888000]  [<00000000406a4558>] bus_for_each_dev+0xd0/0x128
[   38.888000]  [<00000000406a76f8>] driver_attach+0x48/0x60
[   38.888000]  [<00000000406a6de8>] bus_add_driver+0x268/0x460
[   38.888000]  [<00000000406a915c>] driver_register+0x124/0x1d0
[   38.888000]  [<00000000405f336c>] __pci_register_driver+0x64/0x78
[   38.888000]  [<00000000401375e4>] serial_pci_driver_init+0x44/0x58

Quoted 4 lines

[   59.084000] timer_interrupt(CPU 3): delayed! cycles 85EBC4C7D rem 2BAF83  next/now 2765C08677/276594D6F4
[   59.140000] bootconsole [ttyB0] disabled
[   59.144000] serial 0000:00:04.1: ttyS1 at MMIO 0xffffffff80000008 (irq = 70, base_baud = 115200) is a 16450
[   59.164000] serial 0000:00:04.1: ttyS2 at MMIO 0xffffffff80000010 (irq = 70, base_baud = 115200) is a 16550A

I confirm this behaviour on the Mako system as well. In my case, 3.18 so royally screws up the serial port that even a power cycle won't recover the console connection to the MP (a sort of parisc equivalent of a BMC) and I have to go down to the machine room to physically yank the power from the system to power down the MP and get the console back. I've added a cc to linux-serial. It looks like there are 20 non merge commits between 3.17 and 3.18. I'm betting because of the MP problem it's got to be somewhere in the serial driver:

cd92208 tty: serial: 8250_mtk: Fix quot calculation
716e115 serial: 8250_pci: remove rts_n override from Baytrail quirk 1ede7dc serial: 8250: Add Quark X1000 to 8250_pci.c
9137568 tty: serial: 8250_core: remove UART_IER_RDI in serial8250_stop_rx()
59b3e89 tty: serial: 8250_core: use the ->line argument as a hint in serial8250_find_match_or_unused()
0aa525d tty: serial: 8250_core: read only RX if there is something in the FIFO
d74d5d1 tty: serial: 8250_core: add run time pm
234abab tty: serial: 8250_core: allow to set ->throttle / ->unthrottle callbacks
2989708 serial: 8250_pci: Add PCI IDs for Intel Braswell 9a1870c serial: 8250: don't use slave_id of dma_slave_config b4756f4 tty: serial: 8250: Add Mediatek UART driver
0b4af1d serial/8250_core: Add reference to uacess.h
b99b121 tty: serial: 8250_core: allow to overwrite & export serial8250_startup()
ae14a79 tty: serial: 8250_core: provide a function to export uart_8250_port
5435d20 serial: 8250: Document serial8250_modem_status() locking a6eec92 Revert "serial: uart: add hw flow control support configuration" c10b739 serial: 8250_hp300: trivial: fix symbol name in #warning message 28e3fb6 serial: Add support for Fintek F81216A LPC to 4 UART e676253 serial/8250: Add support for RS485 IOCTLs
91f9d33 module: make it possible to have unsafe, tainting module params

Bisecting is going to be a pain because of the physical power cycle problem on a racked system.

James

Peter Hurley

2015-01-01 04:56 UTC #2 lore raw

Quoted 7 lines · James Bottomley

Quoted 6 lines · Helge Deller
While testing kernel 3.18-rc4 I'm facing a problem with serial console.
I'm seeing at bootup this message:
[   17.724000] console [ttyS0] disabled
after that it's just hanging.

Quoted 6 lines

Quoted 6 lines
It seems as if ttyS0 is somehow being reprogrammed which then disturbs the serial ports on the receiver side (in my case a HP PCI Diva Serial [GSP] Multiport UART). Any idea what changed between 3.17 and 3.18 which have caused this behavior ? Full log below.
Helge

I apologize that I did not see this email back in November; I was having some email trouble at the time.

Quoted 61 lines

Quoted 40 lines
serial driver: drivers/tty/serial/8250/8250_pci.c
PCI info:
00:04.1 Serial controller: Hewlett-Packard Company Diva Serial [GSP] Multiport UART (rev 03) (prog-if 02 [16550])
Subsystem: Hewlett-Packard Company Device 1283
Flags: medium devsel, IRQ 70
Memory at ffffffff80000000 (32-bit, non-prefetchable) [size=4K]
I/O ports at 0040 [size=64]
Capabilities: [48] Power Management version 2
Kernel driver in use: serial
dmesg after bootup:
[   17.708000] Serial: 8250/16550 driver, 8 ports, IRQ sharing enabled
[   17.724000] serial 0000:00:04.1: enabling device (0142 -> 0143)
[   17.724000] console [ttyS0] disabled
[   17.880000] serial 0000:00:04.1: ttyS0 at MMIO 0xffffffff80000000 (irq = 70, base_baud = 115200) is a 16550A
[   17.996000] console [ttyS0] enabled
[   38.888000] INFO: rcu_sched detected stalls on CPUs/tasks: { 3} (detected by 1, t=5252 jiffies, g=-290, c=-291, q=2)
[   38.888000] Task dump for CPU 3:
[   38.888000] swapper/0       R  running task        0     1      0 0x00000004
[   38.888000] Backtrace:
[   38.888000]  [<0000000040200848>] vprintk_emit+0x570/0x5f8
[   38.888000]  [<0000000040200bdc>] printk+0x64/0x78
[   38.888000]  [<0000000040201fc0>] register_console+0x438/0x550
[   38.888000]  [<0000000040688bb8>] uart_add_one_port+0x400/0x5d0
[   38.888000]  [<000000004068e6d4>] serial8250_register_8250_port+0x3e4/0x448
[   38.888000]  [<0000000040695f44>] pciserial_init_ports+0x22c/0x2c8
[   38.888000]  [<0000000040696628>] pciserial_init_one+0x250/0x2e0
[   38.888000]  [<00000000405f3880>] pci_device_probe+0xb0/0x150
[   38.888000]  [<00000000406a8244>] driver_probe_device+0x204/0x570
[   38.888000]  [<00000000406a8728>] __driver_attach+0xe0/0x158
[   38.888000]  [<00000000406a4558>] bus_for_each_dev+0xd0/0x128
[   38.888000]  [<00000000406a76f8>] driver_attach+0x48/0x60
[   38.888000]  [<00000000406a6de8>] bus_add_driver+0x268/0x460
[   38.888000]  [<00000000406a915c>] driver_register+0x124/0x1d0
[   38.888000]  [<00000000405f336c>] __pci_register_driver+0x64/0x78
[   38.888000]  [<00000000401375e4>] serial_pci_driver_init+0x44/0x58
Quoted 4 lines
[   59.084000] timer_interrupt(CPU 3): delayed! cycles 85EBC4C7D rem 2BAF83  next/now 2765C08677/276594D6F4
[   59.140000] bootconsole [ttyB0] disabled
[   59.144000] serial 0000:00:04.1: ttyS1 at MMIO 0xffffffff80000008 (irq = 70, base_baud = 115200) is a 16450
[   59.164000] serial 0000:00:04.1: ttyS2 at MMIO 0xffffffff80000010 (irq = 70, base_baud = 115200) is a 16550A
I confirm this behaviour on the Mako system as well. In my case, 3.18 so royally screws up the serial port that even a power cycle won't recover the console connection to the MP (a sort of parisc equivalent of a BMC) and I have to go down to the machine room to physically yank the power from the system to power down the MP and get the console back. I've added a cc to linux-serial. It looks like there are 20 non merge commits between 3.17 and 3.18. I'm betting because of the MP problem it's got to be somewhere in the serial driver:
cd92208 tty: serial: 8250_mtk: Fix quot calculation 716e115 serial: 8250_pci: remove rts_n override from Baytrail quirk 1ede7dc serial: 8250: Add Quark X1000 to 8250_pci.c 9137568 tty: serial: 8250_core: remove UART_IER_RDI in serial8250_stop_rx()

Quoted 2 lines

59b3e89 tty: serial: 8250_core: use the ->line argument as a hint in serial8250_find_match_or_unused()

^^^^^^^^^
This commit would be my first guess, but a complete dmesg up to boot failure would be helpful in narrowing down the problem. There are about 50 ways to initialize the 8250 port (which is part of the problem).

Regards,
Peter Hurley

Quoted 22 lines

0aa525d tty: serial: 8250_core: read only RX if there is something in the FIFO
d74d5d1 tty: serial: 8250_core: add run time pm
234abab tty: serial: 8250_core: allow to set ->throttle / ->unthrottle callbacks
2989708 serial: 8250_pci: Add PCI IDs for Intel Braswell 9a1870c serial: 8250: don't use slave_id of dma_slave_config b4756f4 tty: serial: 8250: Add Mediatek UART driver
0b4af1d serial/8250_core: Add reference to uacess.h
b99b121 tty: serial: 8250_core: allow to overwrite & export serial8250_startup()
ae14a79 tty: serial: 8250_core: provide a function to export uart_8250_port
5435d20 serial: 8250: Document serial8250_modem_status() locking a6eec92 Revert "serial: uart: add hw flow control support configuration" c10b739 serial: 8250_hp300: trivial: fix symbol name in #warning message 28e3fb6 serial: Add support for Fintek F81216A LPC to 4 UART e676253 serial/8250: Add support for RS485 IOCTLs
91f9d33 module: make it possible to have unsafe, tainting module params
Bisecting is going to be a pain because of the physical power cycle problem on a racked system.

James Bottomley

2015-01-01 08:52 UTC #3 lore raw

Quoted 79 lines · Peter Hurley

Quoted 7 lines · James Bottomley
Quoted 6 lines · Helge Deller
While testing kernel 3.18-rc4 I'm facing a problem with serial console.
I'm seeing at bootup this message:
[   17.724000] console [ttyS0] disabled
after that it's just hanging.
Quoted 6 lines
Quoted 6 lines
It seems as if ttyS0 is somehow being reprogrammed which then disturbs the serial ports on the receiver side (in my case a HP PCI Diva Serial [GSP] Multiport UART). Any idea what changed between 3.17 and 3.18 which have caused this behavior ? Full log below.
Helge
I apologize that I did not see this email back in November; I was having some email trouble at the time.
Quoted 59 lines
Quoted 40 lines
serial driver: drivers/tty/serial/8250/8250_pci.c
PCI info:
00:04.1 Serial controller: Hewlett-Packard Company Diva Serial [GSP] Multiport UART (rev 03) (prog-if 02 [16550])
Subsystem: Hewlett-Packard Company Device 1283
Flags: medium devsel, IRQ 70
Memory at ffffffff80000000 (32-bit, non-prefetchable) [size=4K]
I/O ports at 0040 [size=64]
Capabilities: [48] Power Management version 2
Kernel driver in use: serial
dmesg after bootup:
[   17.708000] Serial: 8250/16550 driver, 8 ports, IRQ sharing enabled
[   17.724000] serial 0000:00:04.1: enabling device (0142 -> 0143)
[   17.724000] console [ttyS0] disabled
[   17.880000] serial 0000:00:04.1: ttyS0 at MMIO 0xffffffff80000000 (irq = 70, base_baud = 115200) is a 16550A
[   17.996000] console [ttyS0] enabled
[   38.888000] INFO: rcu_sched detected stalls on CPUs/tasks: { 3} (detected by 1, t=5252 jiffies, g=-290, c=-291, q=2)
[   38.888000] Task dump for CPU 3:
[   38.888000] swapper/0       R  running task        0     1      0 0x00000004
[   38.888000] Backtrace:
[   38.888000]  [<0000000040200848>] vprintk_emit+0x570/0x5f8
[   38.888000]  [<0000000040200bdc>] printk+0x64/0x78
[   38.888000]  [<0000000040201fc0>] register_console+0x438/0x550
[   38.888000]  [<0000000040688bb8>] uart_add_one_port+0x400/0x5d0
[   38.888000]  [<000000004068e6d4>] serial8250_register_8250_port+0x3e4/0x448
[   38.888000]  [<0000000040695f44>] pciserial_init_ports+0x22c/0x2c8
[   38.888000]  [<0000000040696628>] pciserial_init_one+0x250/0x2e0
[   38.888000]  [<00000000405f3880>] pci_device_probe+0xb0/0x150
[   38.888000]  [<00000000406a8244>] driver_probe_device+0x204/0x570
[   38.888000]  [<00000000406a8728>] __driver_attach+0xe0/0x158
[   38.888000]  [<00000000406a4558>] bus_for_each_dev+0xd0/0x128
[   38.888000]  [<00000000406a76f8>] driver_attach+0x48/0x60
[   38.888000]  [<00000000406a6de8>] bus_add_driver+0x268/0x460
[   38.888000]  [<00000000406a915c>] driver_register+0x124/0x1d0
[   38.888000]  [<00000000405f336c>] __pci_register_driver+0x64/0x78
[   38.888000]  [<00000000401375e4>] serial_pci_driver_init+0x44/0x58
Quoted 4 lines
[   59.084000] timer_interrupt(CPU 3): delayed! cycles 85EBC4C7D rem 2BAF83  next/now 2765C08677/276594D6F4
[   59.140000] bootconsole [ttyB0] disabled
[   59.144000] serial 0000:00:04.1: ttyS1 at MMIO 0xffffffff80000008 (irq = 70, base_baud = 115200) is a 16450
[   59.164000] serial 0000:00:04.1: ttyS2 at MMIO 0xffffffff80000010 (irq = 70, base_baud = 115200) is a 16550A
I confirm this behaviour on the Mako system as well. In my case, 3.18 so royally screws up the serial port that even a power cycle won't recover the console connection to the MP (a sort of parisc equivalent of a BMC) and I have to go down to the machine room to physically yank the power from the system to power down the MP and get the console back. I've added a cc to linux-serial. It looks like there are 20 non merge commits between 3.17 and 3.18. I'm betting because of the MP problem it's got to be somewhere in the serial driver:
cd92208 tty: serial: 8250_mtk: Fix quot calculation 716e115 serial: 8250_pci: remove rts_n override from Baytrail quirk 1ede7dc serial: 8250: Add Quark X1000 to 8250_pci.c 9137568 tty: serial: 8250_core: remove UART_IER_RDI in serial8250_stop_rx()

Quoted 6 lines

Quoted 2 lines
59b3e89 tty: serial: 8250_core: use the ->line argument as a hint in serial8250_find_match_or_unused()
^^^^^^^^^
This commit would be my first guess, but a complete dmesg up to boot failure would be helpful in narrowing down the problem. There are about 50 ways to initialize the 8250 port (which is part of the problem).

Well, bisection says it's not this one. Unfortunately, we crap out at this one:

ae14a79 tty: serial: 8250_core: provide a function to export uart_8250_port

CC drivers/tty/serial/8250/8250_core.o
drivers/tty/serial/8250/8250_core.c: In function 'serial8250_ioctl':
drivers/tty/serial/8250/8250_core.c:2857: error: 'TIOCSRS485' undeclared (first use in this function) drivers/tty/serial/8250/8250_core.c:2857: error: (Each undeclared identifier is reported only once drivers/tty/serial/8250/8250_core.c:2857: error: for each function it appears in.)
drivers/tty/serial/8250/8250_core.c:2858: error: implicit declaration of function 'copy_from_user' drivers/tty/serial/8250/8250_core.c:2869: error: 'TIOCGRS485' undeclared (first use in this function) drivers/tty/serial/8250/8250_core.c:2870: error: implicit declaration of function 'copy_to_user'
make[4]: *** [drivers/tty/serial/8250/8250_core.o] Error 1 make[3]: *** [drivers/tty/serial/8250] Error 2
make[2]: *** [drivers/tty/serial] Error 2
make[1]: *** [drivers/tty] Error 2

I'll work out how to fix it in the morning ... but really, having a bisectable tree is supposed to be the first rule of a maintainer.

James

James Bottomley

2015-01-01 22:06 UTC #4 lore raw

Quoted 112 lines · James Bottomley

Quoted 79 lines · Peter Hurley
Quoted 7 lines · James Bottomley
Quoted 6 lines · Helge Deller
While testing kernel 3.18-rc4 I'm facing a problem with serial console.
I'm seeing at bootup this message:
[   17.724000] console [ttyS0] disabled
after that it's just hanging.
Quoted 6 lines
Quoted 6 lines
It seems as if ttyS0 is somehow being reprogrammed which then disturbs the serial ports on the receiver side (in my case a HP PCI Diva Serial [GSP] Multiport UART). Any idea what changed between 3.17 and 3.18 which have caused this behavior ? Full log below.
Helge
I apologize that I did not see this email back in November; I was having some email trouble at the time.
Quoted 59 lines
Quoted 40 lines
serial driver: drivers/tty/serial/8250/8250_pci.c
PCI info:
00:04.1 Serial controller: Hewlett-Packard Company Diva Serial [GSP] Multiport UART (rev 03) (prog-if 02 [16550])
Subsystem: Hewlett-Packard Company Device 1283
Flags: medium devsel, IRQ 70
Memory at ffffffff80000000 (32-bit, non-prefetchable) [size=4K]
I/O ports at 0040 [size=64]
Capabilities: [48] Power Management version 2
Kernel driver in use: serial
dmesg after bootup:
[   17.708000] Serial: 8250/16550 driver, 8 ports, IRQ sharing enabled
[   17.724000] serial 0000:00:04.1: enabling device (0142 -> 0143)
[   17.724000] console [ttyS0] disabled
[   17.880000] serial 0000:00:04.1: ttyS0 at MMIO 0xffffffff80000000 (irq = 70, base_baud = 115200) is a 16550A
[   17.996000] console [ttyS0] enabled
[   38.888000] INFO: rcu_sched detected stalls on CPUs/tasks: { 3} (detected by 1, t=5252 jiffies, g=-290, c=-291, q=2)
[   38.888000] Task dump for CPU 3:
[   38.888000] swapper/0       R  running task        0     1      0 0x00000004
[   38.888000] Backtrace:
[   38.888000]  [<0000000040200848>] vprintk_emit+0x570/0x5f8
[   38.888000]  [<0000000040200bdc>] printk+0x64/0x78
[   38.888000]  [<0000000040201fc0>] register_console+0x438/0x550
[   38.888000]  [<0000000040688bb8>] uart_add_one_port+0x400/0x5d0
[   38.888000]  [<000000004068e6d4>] serial8250_register_8250_port+0x3e4/0x448
[   38.888000]  [<0000000040695f44>] pciserial_init_ports+0x22c/0x2c8
[   38.888000]  [<0000000040696628>] pciserial_init_one+0x250/0x2e0
[   38.888000]  [<00000000405f3880>] pci_device_probe+0xb0/0x150
[   38.888000]  [<00000000406a8244>] driver_probe_device+0x204/0x570
[   38.888000]  [<00000000406a8728>] __driver_attach+0xe0/0x158
[   38.888000]  [<00000000406a4558>] bus_for_each_dev+0xd0/0x128
[   38.888000]  [<00000000406a76f8>] driver_attach+0x48/0x60
[   38.888000]  [<00000000406a6de8>] bus_add_driver+0x268/0x460
[   38.888000]  [<00000000406a915c>] driver_register+0x124/0x1d0
[   38.888000]  [<00000000405f336c>] __pci_register_driver+0x64/0x78
[   38.888000]  [<00000000401375e4>] serial_pci_driver_init+0x44/0x58
Quoted 4 lines
[   59.084000] timer_interrupt(CPU 3): delayed! cycles 85EBC4C7D rem 2BAF83  next/now 2765C08677/276594D6F4
[   59.140000] bootconsole [ttyB0] disabled
[   59.144000] serial 0000:00:04.1: ttyS1 at MMIO 0xffffffff80000008 (irq = 70, base_baud = 115200) is a 16450
[   59.164000] serial 0000:00:04.1: ttyS2 at MMIO 0xffffffff80000010 (irq = 70, base_baud = 115200) is a 16550A
I confirm this behaviour on the Mako system as well. In my case, 3.18 so royally screws up the serial port that even a power cycle won't recover the console connection to the MP (a sort of parisc equivalent of a BMC) and I have to go down to the machine room to physically yank the power from the system to power down the MP and get the console back. I've added a cc to linux-serial. It looks like there are 20 non merge commits between 3.17 and 3.18. I'm betting because of the MP problem it's got to be somewhere in the serial driver:
cd92208 tty: serial: 8250_mtk: Fix quot calculation 716e115 serial: 8250_pci: remove rts_n override from Baytrail quirk 1ede7dc serial: 8250: Add Quark X1000 to 8250_pci.c 9137568 tty: serial: 8250_core: remove UART_IER_RDI in serial8250_stop_rx()
Quoted 6 lines
Quoted 2 lines
59b3e89 tty: serial: 8250_core: use the ->line argument as a hint in serial8250_find_match_or_unused()
^^^^^^^^^
This commit would be my first guess, but a complete dmesg up to boot failure would be helpful in narrowing down the problem. There are about 50 ways to initialize the 8250 port (which is part of the problem).
Well, bisection says it's not this one. Unfortunately, we crap out at this one:
ae14a79 tty: serial: 8250_core: provide a function to export uart_8250_port
CC drivers/tty/serial/8250/8250_core.o
drivers/tty/serial/8250/8250_core.c: In function 'serial8250_ioctl':
drivers/tty/serial/8250/8250_core.c:2857: error: 'TIOCSRS485' undeclared (first use in this function) drivers/tty/serial/8250/8250_core.c:2857: error: (Each undeclared identifier is reported only once drivers/tty/serial/8250/8250_core.c:2857: error: for each function it appears in.)
drivers/tty/serial/8250/8250_core.c:2858: error: implicit declaration of function 'copy_from_user' drivers/tty/serial/8250/8250_core.c:2869: error: 'TIOCGRS485' undeclared (first use in this function) drivers/tty/serial/8250/8250_core.c:2870: error: implicit declaration of function 'copy_to_user'
make[4]: *** [drivers/tty/serial/8250/8250_core.o] Error 1 make[3]: *** [drivers/tty/serial/8250] Error 2
make[2]: *** [drivers/tty/serial] Error 2
make[1]: *** [drivers/tty] Error 2

Quoted 2 lines

I'll work out how to fix it in the morning ... but really, having a bisectable tree is supposed to be the first rule of a maintainer.

OK, I managed to bisect the rest of the tree compensating for the build failure. This is the failing commit (cc's added):

commit 2f2dafe77df2c78e189a9fa6b1879dffd06ae5a1

Author: Sudip Mukherjee <[email protected]>
Date:   Mon Sep 1 20:49:43 2014 +0530

serial: serial_core.c: printk replacement

I've confirmed by reverting against 3.19-rc2 and the system boots again. This looks like a symptom of underlying problems within the dev_ print helper accessors, so I'll dig further, but we'll need this reverted in the meantime.

James

Sudip Mukherjee

2015-01-02 05:34 UTC #5 lore raw

Quoted 118 lines · James Bottomley

Quoted 108 lines · James Bottomley
Quoted 76 lines · Peter Hurley
Quoted 7 lines · James Bottomley
Quoted 6 lines · Helge Deller
While testing kernel 3.18-rc4 I'm facing a problem with serial console.
I'm seeing at bootup this message:
[   17.724000] console [ttyS0] disabled
after that it's just hanging.
Quoted 6 lines
Quoted 6 lines
It seems as if ttyS0 is somehow being reprogrammed which then disturbs the serial ports on the receiver side (in my case a HP PCI Diva Serial [GSP] Multiport UART). Any idea what changed between 3.17 and 3.18 which have caused this behavior ? Full log below.
Helge
I apologize that I did not see this email back in November; I was having some email trouble at the time.
Quoted 58 lines
Quoted 40 lines
serial driver: drivers/tty/serial/8250/8250_pci.c
PCI info:
00:04.1 Serial controller: Hewlett-Packard Company Diva Serial [GSP] Multiport UART (rev 03) (prog-if 02 [16550])
Subsystem: Hewlett-Packard Company Device 1283
Flags: medium devsel, IRQ 70
Memory at ffffffff80000000 (32-bit, non-prefetchable) [size=4K]
I/O ports at 0040 [size=64]
Capabilities: [48] Power Management version 2
Kernel driver in use: serial
dmesg after bootup:
[   17.708000] Serial: 8250/16550 driver, 8 ports, IRQ sharing enabled
[   17.724000] serial 0000:00:04.1: enabling device (0142 -> 0143)
[   17.724000] console [ttyS0] disabled
[   17.880000] serial 0000:00:04.1: ttyS0 at MMIO 0xffffffff80000000 (irq = 70, base_baud = 115200) is a 16550A
[   17.996000] console [ttyS0] enabled
[   38.888000] INFO: rcu_sched detected stalls on CPUs/tasks: { 3} (detected by 1, t=5252 jiffies, g=-290, c=-291, q=2)
[   38.888000] Task dump for CPU 3:
[   38.888000] swapper/0       R  running task        0     1      0 0x00000004
[   38.888000] Backtrace:
[   38.888000]  [<0000000040200848>] vprintk_emit+0x570/0x5f8
[   38.888000]  [<0000000040200bdc>] printk+0x64/0x78
[   38.888000]  [<0000000040201fc0>] register_console+0x438/0x550
[   38.888000]  [<0000000040688bb8>] uart_add_one_port+0x400/0x5d0
[   38.888000]  [<000000004068e6d4>] serial8250_register_8250_port+0x3e4/0x448
[   38.888000]  [<0000000040695f44>] pciserial_init_ports+0x22c/0x2c8
[   38.888000]  [<0000000040696628>] pciserial_init_one+0x250/0x2e0
[   38.888000]  [<00000000405f3880>] pci_device_probe+0xb0/0x150
[   38.888000]  [<00000000406a8244>] driver_probe_device+0x204/0x570
[   38.888000]  [<00000000406a8728>] __driver_attach+0xe0/0x158
[   38.888000]  [<00000000406a4558>] bus_for_each_dev+0xd0/0x128
[   38.888000]  [<00000000406a76f8>] driver_attach+0x48/0x60
[   38.888000]  [<00000000406a6de8>] bus_add_driver+0x268/0x460
[   38.888000]  [<00000000406a915c>] driver_register+0x124/0x1d0
[   38.888000]  [<00000000405f336c>] __pci_register_driver+0x64/0x78
[   38.888000]  [<00000000401375e4>] serial_pci_driver_init+0x44/0x58
Quoted 4 lines
[   59.084000] timer_interrupt(CPU 3): delayed! cycles 85EBC4C7D rem 2BAF83  next/now 2765C08677/276594D6F4
[   59.140000] bootconsole [ttyB0] disabled
[   59.144000] serial 0000:00:04.1: ttyS1 at MMIO 0xffffffff80000008 (irq = 70, base_baud = 115200) is a 16450
[   59.164000] serial 0000:00:04.1: ttyS2 at MMIO 0xffffffff80000010 (irq = 70, base_baud = 115200) is a 16550A
I confirm this behaviour on the Mako system as well. In my case, 3.18 so royally screws up the serial port that even a power cycle won't recover the console connection to the MP (a sort of parisc equivalent of a BMC) and I have to go down to the machine room to physically yank the power from the system to power down the MP and get the console back. I've added a cc to linux-serial. It looks like there are 20 non merge commits between 3.17 and 3.18. I'm betting because of the MP problem it's got to be somewhere in the serial driver:
cd92208 tty: serial: 8250_mtk: Fix quot calculation 716e115 serial: 8250_pci: remove rts_n override from Baytrail quirk 1ede7dc serial: 8250: Add Quark X1000 to 8250_pci.c 9137568 tty: serial: 8250_core: remove UART_IER_RDI in serial8250_stop_rx()
Quoted 6 lines
Quoted 2 lines
59b3e89 tty: serial: 8250_core: use the ->line argument as a hint in serial8250_find_match_or_unused()
^^^^^^^^^
This commit would be my first guess, but a complete dmesg up to boot failure would be helpful in narrowing down the problem. There are about 50 ways to initialize the 8250 port (which is part of the problem).
Well, bisection says it's not this one. Unfortunately, we crap out at this one:
ae14a79 tty: serial: 8250_core: provide a function to export uart_8250_port
   CC      drivers/tty/serial/8250/8250_core.o
drivers/tty/serial/8250/8250_core.c: In function 'serial8250_ioctl':
drivers/tty/serial/8250/8250_core.c:2857: error: 'TIOCSRS485' undeclared (first use in this function) drivers/tty/serial/8250/8250_core.c:2857: error: (Each undeclared identifier is reported only once drivers/tty/serial/8250/8250_core.c:2857: error: for each function it appears in.)
drivers/tty/serial/8250/8250_core.c:2858: error: implicit declaration of function 'copy_from_user' drivers/tty/serial/8250/8250_core.c:2869: error: 'TIOCGRS485' undeclared (first use in this function) drivers/tty/serial/8250/8250_core.c:2870: error: implicit declaration of function 'copy_to_user'
make[4]: *** [drivers/tty/serial/8250/8250_core.o] Error 1 make[3]: *** [drivers/tty/serial/8250] Error 2
make[2]: *** [drivers/tty/serial] Error 2
make[1]: *** [drivers/tty] Error 2
Quoted 2 lines
I'll work out how to fix it in the morning ... but really, having a bisectable tree is supposed to be the first rule of a maintainer.
OK, I managed to bisect the rest of the tree compensating for the build failure. This is the failing commit (cc's added):
commit 2f2dafe77df2c78e189a9fa6b1879dffd06ae5a1
Author: Sudip Mukherjee <[email protected]>
Date:   Mon Sep 1 20:49:43 2014 +0530

Quoted 6 lines

serial: serial_core.c: printk replacement
I've confirmed by reverting against 3.19-rc2 and the system boots again. This looks like a symptom of underlying problems within the dev_ print helper accessors, so I'll dig further, but we'll need this reverted in the meantime.

Sure.
can dev_print hang the machine? if dev is NULL, it will just print using printk. in vprintk_emit(), there is an Ouch for printk recursing into itself. can that be the cause? and, can i help you somehow to find out the root cause of this ?

thanks
sudip

Quoted 4 lines

James

James Bottomley

2015-01-02 07:26 UTC #6 lore raw

Quoted 125 lines · Sudip Mukherjee

Quoted 118 lines · James Bottomley
Quoted 108 lines · James Bottomley
Quoted 76 lines · Peter Hurley
Quoted 7 lines · James Bottomley
Quoted 6 lines · Helge Deller
While testing kernel 3.18-rc4 I'm facing a problem with serial console.
I'm seeing at bootup this message:
[   17.724000] console [ttyS0] disabled
after that it's just hanging.
Quoted 6 lines
Quoted 6 lines
It seems as if ttyS0 is somehow being reprogrammed which then disturbs the serial ports on the receiver side (in my case a HP PCI Diva Serial [GSP] Multiport UART). Any idea what changed between 3.17 and 3.18 which have caused this behavior ? Full log below.
Helge
I apologize that I did not see this email back in November; I was having some email trouble at the time.
Quoted 58 lines
Quoted 40 lines
serial driver: drivers/tty/serial/8250/8250_pci.c
PCI info:
00:04.1 Serial controller: Hewlett-Packard Company Diva Serial [GSP] Multiport UART (rev 03) (prog-if 02 [16550])
Subsystem: Hewlett-Packard Company Device 1283
Flags: medium devsel, IRQ 70
Memory at ffffffff80000000 (32-bit, non-prefetchable) [size=4K]
I/O ports at 0040 [size=64]
Capabilities: [48] Power Management version 2
Kernel driver in use: serial
dmesg after bootup:
[   17.708000] Serial: 8250/16550 driver, 8 ports, IRQ sharing enabled
[   17.724000] serial 0000:00:04.1: enabling device (0142 -> 0143)
[   17.724000] console [ttyS0] disabled
[   17.880000] serial 0000:00:04.1: ttyS0 at MMIO 0xffffffff80000000 (irq = 70, base_baud = 115200) is a 16550A
[   17.996000] console [ttyS0] enabled
[   38.888000] INFO: rcu_sched detected stalls on CPUs/tasks: { 3} (detected by 1, t=5252 jiffies, g=-290, c=-291, q=2)
[   38.888000] Task dump for CPU 3:
[   38.888000] swapper/0       R  running task        0     1      0 0x00000004
[   38.888000] Backtrace:
[   38.888000]  [<0000000040200848>] vprintk_emit+0x570/0x5f8
[   38.888000]  [<0000000040200bdc>] printk+0x64/0x78
[   38.888000]  [<0000000040201fc0>] register_console+0x438/0x550
[   38.888000]  [<0000000040688bb8>] uart_add_one_port+0x400/0x5d0
[   38.888000]  [<000000004068e6d4>] serial8250_register_8250_port+0x3e4/0x448
[   38.888000]  [<0000000040695f44>] pciserial_init_ports+0x22c/0x2c8
[   38.888000]  [<0000000040696628>] pciserial_init_one+0x250/0x2e0
[   38.888000]  [<00000000405f3880>] pci_device_probe+0xb0/0x150
[   38.888000]  [<00000000406a8244>] driver_probe_device+0x204/0x570
[   38.888000]  [<00000000406a8728>] __driver_attach+0xe0/0x158
[   38.888000]  [<00000000406a4558>] bus_for_each_dev+0xd0/0x128
[   38.888000]  [<00000000406a76f8>] driver_attach+0x48/0x60
[   38.888000]  [<00000000406a6de8>] bus_add_driver+0x268/0x460
[   38.888000]  [<00000000406a915c>] driver_register+0x124/0x1d0
[   38.888000]  [<00000000405f336c>] __pci_register_driver+0x64/0x78
[   38.888000]  [<00000000401375e4>] serial_pci_driver_init+0x44/0x58
Quoted 4 lines
[   59.084000] timer_interrupt(CPU 3): delayed! cycles 85EBC4C7D rem 2BAF83  next/now 2765C08677/276594D6F4
[   59.140000] bootconsole [ttyB0] disabled
[   59.144000] serial 0000:00:04.1: ttyS1 at MMIO 0xffffffff80000008 (irq = 70, base_baud = 115200) is a 16450
[   59.164000] serial 0000:00:04.1: ttyS2 at MMIO 0xffffffff80000010 (irq = 70, base_baud = 115200) is a 16550A
I confirm this behaviour on the Mako system as well. In my case, 3.18 so royally screws up the serial port that even a power cycle won't recover the console connection to the MP (a sort of parisc equivalent of a BMC) and I have to go down to the machine room to physically yank the power from the system to power down the MP and get the console back. I've added a cc to linux-serial. It looks like there are 20 non merge commits between 3.17 and 3.18. I'm betting because of the MP problem it's got to be somewhere in the serial driver:
cd92208 tty: serial: 8250_mtk: Fix quot calculation 716e115 serial: 8250_pci: remove rts_n override from Baytrail quirk 1ede7dc serial: 8250: Add Quark X1000 to 8250_pci.c 9137568 tty: serial: 8250_core: remove UART_IER_RDI in serial8250_stop_rx()
Quoted 6 lines
Quoted 2 lines
59b3e89 tty: serial: 8250_core: use the ->line argument as a hint in serial8250_find_match_or_unused()
^^^^^^^^^
This commit would be my first guess, but a complete dmesg up to boot failure would be helpful in narrowing down the problem. There are about 50 ways to initialize the 8250 port (which is part of the problem).
Well, bisection says it's not this one. Unfortunately, we crap out at this one:
ae14a79 tty: serial: 8250_core: provide a function to export uart_8250_port
   CC      drivers/tty/serial/8250/8250_core.o
drivers/tty/serial/8250/8250_core.c: In function 'serial8250_ioctl':
drivers/tty/serial/8250/8250_core.c:2857: error: 'TIOCSRS485' undeclared (first use in this function) drivers/tty/serial/8250/8250_core.c:2857: error: (Each undeclared identifier is reported only once drivers/tty/serial/8250/8250_core.c:2857: error: for each function it appears in.)
drivers/tty/serial/8250/8250_core.c:2858: error: implicit declaration of function 'copy_from_user' drivers/tty/serial/8250/8250_core.c:2869: error: 'TIOCGRS485' undeclared (first use in this function) drivers/tty/serial/8250/8250_core.c:2870: error: implicit declaration of function 'copy_to_user'
make[4]: *** [drivers/tty/serial/8250/8250_core.o] Error 1 make[3]: *** [drivers/tty/serial/8250] Error 2
make[2]: *** [drivers/tty/serial] Error 2
make[1]: *** [drivers/tty] Error 2
Quoted 2 lines
I'll work out how to fix it in the morning ... but really, having a bisectable tree is supposed to be the first rule of a maintainer.
OK, I managed to bisect the rest of the tree compensating for the build failure. This is the failing commit (cc's added):
commit 2f2dafe77df2c78e189a9fa6b1879dffd06ae5a1
Author: Sudip Mukherjee <[email protected]>
Date:   Mon Sep 1 20:49:43 2014 +0530
Quoted 6 lines
serial: serial_core.c: printk replacement
I've confirmed by reverting against 3.19-rc2 and the system boots again. This looks like a symptom of underlying problems within the dev_ print helper accessors, so I'll dig further, but we'll need this reverted in the meantime.

Quoted 6 lines

Sure.
can dev_print hang the machine? if dev is NULL, it will just print using printk.
in vprintk_emit(), there is an Ouch for printk recursing into itself. can that be the cause?
and, can i help you somehow to find out the root cause of this ?

It's definitely to do with dev_printk having a different call path from printk. I suspect one of the called functions overruns its stack. Unless you have a stack grows up machine, there's probably no way to reproduce (if the stack overrun suspicion is correct). Visual inspection might turn up a clue: it's probably an array written beyond bounds somewhere in the call chain.

James

James Bottomley

2015-01-02 04:32 UTC #7 lore raw

In reply to James Bottomley

Quoted 5 lines · James Bottomley

I confirm this behaviour on the Mako system as well. In my case, 3.18 so royally screws up the serial port that even a power cycle won't recover the console connection to the MP (a sort of parisc equivalent of a BMC) and I have to go down to the machine room to physically yank the power from the system to power down the MP and get the console back.

For those in parisc land following along, I've discovered that a remote power down followed by a diagnostic reset of the MP will reconnect the console, thus obviating trips to unplug the actual system.

James