[Fwd: [parisc-linux] Problems with raw interface.]

[Grant Grundler]

On Fri, Sep 19, 2003 at 05:34:04PM +0100, Stephen C. Tweedie wrote:
> > > But when I use the raw interface I get garbage. For instance please
> > > look at the output below. I am reading the 1st sector of the disk,
> > > which is the boot sector, When I use the block device /dev/sda I get
> > > my expected output, whereas when I use the raw interface I get
> > > garbage. Can any one explain? The machine I am using is an L Class. 
> 
> Do you _ever_ get valid output, or is raw always failing?  There may
> well be a cache coherency point being missed.

I was able to consistently reproduce this problem on a c3000 (400Mhz
PA8500). That's running 2.4.22 kernel.

> The key places are rw_raw_dev(), where we set up the virtual address to
> physical page mappings, and brw_kiovec(), where the actual physical page
> IO is done.

ok - I should try again with 2.6 kernel and look again.
But I'm certainly no vm/cache expert.

grant