Subject: Re: sun3: si_dma_alloc: excessive xlen=0x10000
To: Jason Thorpe <thorpej@wasabisystems.com>
From: Manuel Bouyer <bouyer@antioche.eu.org>
List: current-users
Date: 06/14/2003 19:25:26
On Sat, Jun 14, 2003 at 10:22:56AM -0700, Jason Thorpe wrote:
> 
> On Saturday, June 14, 2003, at 10:21  AM, Izumi Tsutsui wrote:
> 
> >There is the following comments in si.c:
> >>>	 * Never attempt single transfers of more than 63k, because
> >>>	 * our count register may be only 16 bits (an OBIO adapter).
> >>>	 * This should never happen since already bounded by minphys().
> >
> >si_minphys() in sys/arch/sun3/dev/si.c limits b_count < MAX_DMA_LEN,
> >but why xlen is larger than MAX_DMA_LEN in si_dma_alloc()?
> 
> The issue here is that the file system code does not use minphys() to 
> clamp the transfers.

And used to honnor MAXBSIZE but doesn't do any more

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
     NetBSD: 24 ans d'experience feront toujours la difference
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