reliable "panic: isa_dmastart: bad bounce buffer"
dwhite at gumbysoft.com
Fri Apr 15 20:13:10 PDT 2005
On Tue, 12 Apr 2005, Mikhail Teterin wrote:
> Whenever I try to mount a floppy disk:
> mount -t msdosfs /dev/fd0 /mnt
> I get:
> panic: isa_dmastart: bad bounce buffer
> The OS is FreeBSD-5.4-STABLE from last night, amd64. dmesg attached.
Probably related to:
fdc0: <floppy drive controller (FDE)> port 0x3f7,0x3f0-0x3f5 irq 6 drq 2
isa_dmainit(2, 40960) failed
fd0: <1440-KB 3.5" drive> on fdc0 drive 0
That message is printed by isa_dmainit() in src/sys/amd64/isa/isa_dma.c.
You might instrument that function and see where its blowing up. I
suspect its getting the buffer from malloc() but the range check below it
Doug White | FreeBSD: The Power to Serve
dwhite at gumbysoft.com | www.FreeBSD.org
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