On 10/25/2016 03:41 PM, Sean Young wrote:
On Mon, Oct 24, 2016 at 04:49:25PM -0500, Nathan Zimmer wrote:
[ 0.974874] system 00:03: Plug and Play ACPI device, IDs PNP0c02 (active)
[ 0.975038] pnp 00:04: parse resource options
[ 0.975048] pnp 00:04: dependent set 0 (acceptable) io min 0x2f8 max 0x2f8 align 1 size 8 flags 0x1
[ 0.975056] pnp 00:04: dependent set 0 (acceptable) irq 3 4 5 6 7 10 11 12 flags 0x1
[ 0.975060] pnp 00:04: dependent set 0 (acceptable) dma <none> (bitmask 0x0) flags 0x0
So here the bios claims that the serial port can use any of 3 to 12 irqs.
[ 1.543636] Serial: 8250/16550 driver, 8 ports, IRQ sharing disabled
Why is this kernel compiled with irq sharing disabled?
Because I first noticed the error on a sles kernel and that is how they
have it set.
The error also occurs with sharing on.
<snip from a 4.8 dmesg with irq sharing enabled>
[ 4.662336] Serial: 8250/16550 driver, 8 ports, IRQ sharing enabled
[ 4.663316] serial 00:03: pnp_assign_resources, try dependent set 0
[ 4.664249] serial 00:03: [io 0x02f8-0x02ff]
[ 4.664913] serial 00:03: device 0000:00:16.1 using irq 5
[ 4.688879] serial 00:03: device 0000:00:1f.3 using irq 10
[ 4.712265] serial 00:03: device 0000:00:16.0 using irq 11
[ 4.735265] serial 00:03: [irq 12]
[ 4.757538] serial 00:03: dma 0 disabled
[ 4.780153] serial 00:03: [dma 18446744073709551615 disabled]
[ 4.802826] serial 00:03: pnp_assign_resources succeeded: current
resources:
[ 4.825758] serial 00:03: [io 0x02f8-0x02ff flags 0x40000101]
[ 4.848625] serial 00:03: [irq 12 flags 0x40000401]
[ 4.871224] serial 00:03: [dma 18446744073709551615 flags 0x50000800]
[ 4.893988] serial 00:03: pnp_start_dev: current resources:
[ 4.916634] serial 00:03: [io 0x02f8-0x02ff flags 0x40000101]
[ 4.939280] serial 00:03: [irq 12 flags 0x40000401]
[ 4.961646] serial 00:03: [dma 18446744073709551615 flags 0x50000800]
[ 4.984180] serial 00:03: set resources
[ 5.006654] serial 00:03: encode 3 resources
[ 5.028545] serial 00:03: encode io 0x2f8-0x2ff decode 0x1
[ 5.050486] serial 00:03: encode irq 12 edge high exclusive (2-byte
descriptor)
[ 5.072593] serial 00:03: encode dma (disabled)
[ 5.094644] serial 00:03: activated
[ 5.136000] 00:03: ttyS1 at I/O 0x2f8 (irq = 12, base_baud = 115200)
is a 16550A
[ 1.565062] serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
The isa probe driver find the serial port.
[ 1.566453] serial 00:04: pnp_assign_resources, try dependent set 0
[ 1.567383] serial 00:04: couldn't assign io 0 (min 0x2f8 max 0x2f8)
But then decides that the port is already in use (the existing serial driver).
[ 1.568366] serial 00:04: pnp_assign_resources failed (-16)
[ 1.569188] serial 00:04: unable to assign resources
[ 1.569924] serial: probe of 00:04 failed with error -16
Please try and boot 3.7.0 with "8250.share_irqs=1", maybe it will pick
irq 3 and it will be happy again, but that is just a guess.
I think I have not fully understood what the failure is. Does the serial
port not work or does the boot hang? What are the symptoms?
With console=ttyS1 the boot will "hang", sometimes it makes it all the
way through but may take 30 minutes, instead of the 2-4 minutes this box
We might be able to fix the problem with a pnp quirk but 3.7 is has not had
any releases for a long time. We will need a reproduction on a concurrent
kernel so a patch can be written for that.
Yes it still happens with 4.8+
I had only started dwelling on 3.6/3.7 since that is where it first
appears and don't have any attachment to those.
Sean
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