Subject: Re: alpha pci pio problems
To: Simon Burge <>
From: Jason R Thorpe <>
List: port-alpha
Date: 06/25/2000 11:08:09
On Wed, Jun 21, 2000 at 03:47:25PM +1000, Simon Burge wrote:

 > I've got a program that's basically:
 > 	u_int32_t vgaIObase;
 > 	alpha_pci_io_enable(1);
 > 	vgaIOBase = (inb(0x3cc) & 0x01) ? 0x3D0 : 0x3B0;
 > and it does roughly:
 > 	mmap(size = 0x40000000, addr = 0x8580000000) = 0x1603ec000
 > 	alpha_pci_io_swiz: abw->abw_addr = 0x1603ec000
 > 	alpha_pci_io_swiz: port = 0x1603f3980
 > 	alpha_pci_io_swiz_inb: return (*port && 0xff);
 > and at the last line the machine hangs hard and needs a reset.

hm.  That's ... odd.  The swizzle code in libalpha certainly appears to
have done the correct thing.  I guess the only issue is if mmap mapped
the correct pages underneath that user VA.

 > If I add a kernel printf to show the K0SEG version (0x8580007980) I at
 > least get a number back (0x3000067) but I've yet to figure out if the
 > number is actually correct, although it being odd means that SuperProbe
 > would think that the display is color and not mono which is right.
 > >From what I understand, while I'm just probing the I/O space I don't
 > need to map anything in with alpha_pci_mem_map() yet, right?

No, that's correct.

Anyway, please get your mmap changes committed to the trunk, and I'll
see what I can do to help you debug this.

        -- Jason R. Thorpe <>