Messages in this thread | | | Subject | Re: console issue since 3.6, console=ttyS1 hangs | From | Nathan Zimmer <> | Date | Wed, 19 Oct 2016 17:13:41 -0500 |
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On 10/19/2016 04:07 AM, Sean Young wrote: > On Tue, Oct 18, 2016 at 02:29:30PM -0500, Nathan Zimmer wrote: >> On Tue, Oct 18, 2016 at 07:05:18PM +0100, Sean Young wrote: >>> On Tue, Oct 18, 2016 at 11:40:04AM -0500, Nathan Zimmer wrote: >>>> 3.7.0 >>>> cat /sys/bus/pnp/drivers/serial/*/resources >>>> state = active >>>> io 0x2f8-0x2ff >>>> irq 12 >>>> dma disabled >>>> >>>> 3.6.0 >>>> :~ # cat /sys/bus/pnp/drivers/serial/*/resources >>>> cat: /sys/bus/pnp/drivers/serial/*/resources: No such file or directory >>> irq 12 for ttyS1? That should be irq 3. The bios is putting bogus information >>> in pnp. Maybe there is rubbish in the bios setup or maybe it's fixed in a >>> newer bios update. >>> >>> So before this change, the kernel would assume irq 3. After this change, >>> the kernel first uses the information in pnp to see where the serial >>> port is. It gets told that it's irq 12 and presumably it runs into all >>> sorts of problems then. If memory serves that's the irq for the ps/2 mouse. >>> >>> The interesting bit is in 3.6.0: >>> >>> setserial >>> /dev/ttyS1, UART: 16550A, Port: 0x02f8, IRQ: 3 >>> >>> becomes in 3.7.0: >>> >>> setserial >>> /dev/ttyS1, UART: 16550A, Port: 0x02f8, IRQ: 12 >>> >>> You should be able to set the right irq with setserial, but obviously >>> that doesn't help you if it fails in early boot. It's not immediately >>> obvious to me what can be done in the kernel for this. Maybe the dmesg >>> output could inspire, thanks. >> Yea the changing irq seemed weird to me too but I couldn't manage a guess to why. >> >> Here are the dmesgs. > So with 3.6.0: > >> [ 2.079980] Serial: 8250/16550 driver, 8 ports, IRQ sharing disabled >> [ 2.100887] serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A >> [ 2.101715] serial 00:04: unable to assign resources >> [ 2.102174] serial: probe of 00:04 failed with error -16 > The pnp probe fails for some reason. I don't understand why. > > With 3.7.0: > >> [ 2.062700] Serial: 8250/16550 driver, 8 ports, IRQ sharing disabled >> [ 2.063250] serial 00:04: [io 0x02f8-0x02ff] >> [ 2.063875] serial 00:04: [irq 12] >> [ 2.064345] serial 00:04: [dma 18446744073709551615 disabled] >> [ 2.065540] serial 00:04: activated >> [ 2.086442] 00:04: ttyS1 at I/O 0x2f8 (irq = 12) is a 16550A > Now the pnp probe succeeds (with broken irq from pnp). > > Can you please check if there is a wrong irq configured in the bios setup > or if there is a bios update available? I don't know why this worked in > the first place. > > > Sean
Apparently this is the latest bios available for these nodes. Also in the bios setup screens I don't see anything for changing irq numbers for serial console. But this is a cluster so sometimes thing get hidden to keep everything uniform as possible.
If you want to point me to the pnp probe code you would be suspicious of I can try to debug and see what is going there.
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