linux-mips
[Top] [All Lists]

Re: Au1550 - Problem access Shared memory from PCI card

To: linux-mips@linux-mips.org
Subject: Re: Au1550 - Problem access Shared memory from PCI card
From: "Alexey Shinkin" <alexshinkin@hotmail.com>
Date: Thu, 16 Sep 2004 18:38:23 +0700
Original-recipient: rfc822;linux-mips@linux-mips.org
Sender: linux-mips-bounce@linux-mips.org

There's no reason why this shouldn't work and it doesn't smell like a hardware problem.



The problem is solved !

The reason was that shared memory on host have been allocated using
__get_free_pages(GFP_KERNEL, get_order(NumberOfBytes))

it returned addresses like 0x8xxxxxxx (KSEG0, cacheable)

I was adviced to use pci_alloc_consistent() instead , this function uses __get_free_pages
but sets some GFP flags and returns addresses like 0xAxxxxxxx (KSEG1).
With this function all works fine !

_________________________________________________________________
Add photos to your messages with MSN 8. Get 2 months FREE*. http://join.msn.com/?page=features/featuredemail


<Prev in Thread] Current Thread [Next in Thread>
  • Re: Au1550 - Problem access Shared memory from PCI card, Alexey Shinkin <=