Subject: Re: sun3: si_dma_alloc: excessive xlen=0x10000
To: Izumi Tsutsui <tsutsui@ceres.dti.ne.jp>
From: Jason Thorpe <thorpej@wasabisystems.com>
List: current-users
Date: 06/14/2003 10:22:56
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.

         -- Jason R. Thorpe <thorpej@wasabisystems.com>