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From: William Waddington <waddington@tahomatech.com>
To: linux-kernel@vger.kernel.org
Subject: kiobufs and highmem
Date: Wed, 17 Jul 2002 11:15:22 -0700	[thread overview]
Message-ID: <3D35B43A.4050804@tahomatech.com> (raw)

Hello All,

I have a 2.4.x char driver which works fine, except in boxes with lots of
memory.

user_buffer -> write() -> map_user_kiobuf() -> pci_map_sg() -> Pci DMA

I'm using the .page/.offset version of the scatterlist, but in the HIGHMEM case,
map_user_kiobuf() seems to return peculiar page addresses.

What is the state of kiobufs/HIGHMEM in 2.4.x?  Do I need to implement
a bounce buffer in the driver?  Some email correspondence indicates so,
but I would be grateful for a definitive word from the kernel folks.

TIA,
Bill Waddington

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                 reply	other threads:[~2002-07-17 18:13 UTC|newest]

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