Re: 2.5.44 serial driver bug with asus pr-dls m/b

Russell King (rmk@arm.linux.org.uk)
Tue, 12 Nov 2002 14:33:06 +0000


On Tue, Nov 12, 2002 at 01:49:46PM +0000, Andrew Walrond wrote:
> Further to the hanging serial output; disabling DEBUG_AUTOCONF in 8250.c
> removes this problem.
>
> So the only remaining problem is when remote console=ENABLED, rather
> than post only, in the bios. If this is a problem at all ?
>
> I assume that remote console=enabled redirects the interrupt 0x10
> “video” requests used to write to the screen and sends the characters to
> the serial port instead, rather than just the POST messages. Since the
> 16bit bios is chucked out when the 32bit linux kernel boots, I don't
> understand why this upsets anything?

Well, it looks like the serial port at 0x3f8 gets unmapped by the bios
when you set remote console=ENABLED. The debug output you've sent all
points towards there being no physical port at 0x3f8.

-- 
Russell King (rmk@arm.linux.org.uk)                The developer of ARM Linux
             http://www.arm.linux.org.uk/personal/aboutme.html

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