From: Alan Chandler <alan@chandlerfamily.org.uk>
To: linux-kernel@vger.kernel.org
Subject: Re: ide-cd problem
Date: Mon, 22 Nov 2004 07:52:28 +0000
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Cc: Jens Axboe <axboe@suse.de>
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On Sunday 21 November 2004 16:13, Alan Chandler wrote:
...
>
> This seems to be some combination of frequently occuring timing problem,
> and the difference treatment in cdrom_newpc_intr to cdrom_pc_intr

I put a ndelay(400) at the head of cdrom_newpc_intr and the problem of DRQ 
being set when there was no data to transfer disappeared.  It appears that my 
hardware is too slow.

I have been reading the ATA/ATAPI - 6 spec, and it implies that the state of 
DRQ line need one pio cycle before being correct and that you should read the 
alternative status register to achieve this.  I tried a simple

HWIF(drive)->INB( IDE_ALTSTATUS_REG);

But that made no difference.


-- 
Alan Chandler
alan@chandlerfamily.org.uk
First they ignore you, then they laugh at you,
 then they fight you, then you win. --Gandhi
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