6 Sep
2012
6 Sep
'12
6:15 p.m.
From: Adam Jackson ajax@redhat.com Date: Thu, 06 Sep 2012 12:51:17 -0400
On Thu, 2012-09-06 at 17:41 +0300, Meelis Roos wrote:
And here the machine hangs. Debugging printk-s reveal that it does not find any active I/O port resources and then continues into initializing the card. Down in igp_read_bios_from_vram() it successfully ioremaps memory region 0 (vram_base=1ff08000000 and size=40000) and tries to read 2 bytes from there and hangs on reading bios[0].
This is probably because...
I think the real issue is that the VRAM bios reading code is buggy, see my other email. It deferences ioremap()'d memory, and that's not allowed.
One must use the proper __iomem pointer accessors, such as readl(), readb(), etc.