Re: Adpter card read old memory value

[Arjan van de Ven <arjanv@redhat.com>]

On Tue, Oct 01, 2002 at 05:44:07PM +0300, Eitan Ben-Nun wrote:
> ok thanks,
> An adapter card on the pci bus send a message to pc i386 Linux to update a memory address. 
> Then it reads the address and sees an old value, even though the pc cpu have performed an update to this memory address. Here is referance to my driver code:
> int update_cluster_operation_mode(unsigned long new_mode, 
> 					    unsigned long phys_addr);
> {
>    unsigned long* vir_addr = 0;
>    vir_addr = __ioremap(phys_addr, PAGE_SIZE, _PAGE_PWT | _PAGE_PCD);
>    *vir_addr = new_mode;
>    return 0;
> }
> phys_addr - is always on page bonderies and the address is between 512M-640M.

this is only a part of the source, is there a full source available?

also your code is already buggy; you should use writel(); and also read up
on PCI posting....

Greetings,
   Arjan van de Ven