sio => uart: one port is gone
smithi at nimnet.asn.au
Mon Sep 15 16:48:41 UTC 2008
On Mon, 15 Sep 2008, Andriy Gapon wrote:
> on 15/09/2008 17:36 Ian Smith said the following:
> > On Mon, 15 Sep 2008, Andriy Gapon wrote:
> > > This is a fairly standard and old machine with 2 COM ports.
> > > Recently (last Friday) I decided to update my RELENG_7 system and also
> > > to transition from sio to uart.
> > > > This what I had before the upgrade:
> > > kernel: sio0: <16550A-compatible COM port> port 0x3f8-0x3ff irq 4 flags
> > > 0x10 on acpi0
> > > kernel: sio0: type 16550A
> > > kernel: sio0: [FILTER]
> > > kernel: sio1: <16550A-compatible COM port> port 0x2e8-0x2ef irq 3 on acpi0
> > > kernel: sio1: type 16550A
> > > kernel: sio1: [FILTER]
> > > > This is what I have now:
> > > uart0: <16550 or compatible> at port 0x3f8-0x3ff irq 4 flags 0x10 on isa0
> > > uart0: [FILTER]
> > > > This is what I have in device.hints for uart:
> > > hint.uart.0.at="isa"
> > > hint.uart.0.port="0x3F8"
> > > hint.uart.0.flags="0x10"
> > > hint.uart.0.irq="4"
> > > hint.uart.1.at="isa"
> > > hint.uart.1.port="0x2F8"
> > but it's shown as 0x2e8 above ..
> > > hint.uart.1.irq="3"
> > > hint.uart.2.at="isa"
> > > > Precisely the same hints (s/uart/sio/) I had for sio.
> > 0x2f8 is 'standard COM2' address .. did sio1 work ok at 0x2e8 before?
> thank you, I guess I had a typo in my hints, but the port did work.
> Looking at the old dmesg I see that sio devices are found 'on acpi0' as
> opposed to uart now being found on 'isa0'.
> Maybe this is another difference.
Does sound a bit odd; looks like the ACPI info trumped hints for sio.
> Maybe sio was attached using some information from acpi, so hints were not
> that important. But maybe the same acpi information is not applied to uart,
> so it does depend on the hints.
Sounds a reasonable theory .. so does fixing that hint find the UART?
Maybe a verbose dmesg would provide more clues re uart's attachment?
> If this guess is correct then this is a regression in sio=>uart transition,
> if not, then I'll just correct my device.hints and shut up :-)
Or both :) You'd think if ACPI info is available uart should use it,
but then if it's attaching to the isa bus instead, maybe not .. hmm.
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