Re: PROBLEM: ide-cd in 2.6.8-2.6.10 and 2.4.26-2.4.28 high cpu use with dma

[Marcel Sebek]

On Sun, Jan 09, 2005 at 04:32:16PM +0100, Jens Axboe wrote:
> On Sun, Jan 09 2005, Hikaru1@xxxxxxxxxxx wrote:
> > A minor mistake. I forgot to state explicitly that the problem only appears
> > with writing audio cds. Writing data cds does not cause problems.
> 
> The change isn't safe, it was made for a reason since some drives
> timeout if the alignment/length isn't correct. It probably is a little
> pessimistic right now, can you see if this just works for you?
> 
> ===== drivers/ide/ide-cd.c 1.105 vs edited =====
> --- 1.105/drivers/ide/ide-cd.c	2005-01-08 06:43:53 +01:00
> +++ edited/drivers/ide/ide-cd.c	2005-01-09 16:31:53 +01:00
> @@ -1915,7 +1915,7 @@
>  		/*
>  		 * check if dma is safe
>  		 */
> -		if ((rq->data_len & mask) || (addr & mask))
> +		if ((rq->data_len & 3) || (addr & mask))
>  			info->dma = 0;
>  	}
> 

I saw the same bug on my computer and this patch fixed it. Now I can
burn audio CDs at 40x speed instead of 24x.


-- 
Marcel Sebek
jabber: sebek@xxxxxxxxx                     ICQ: 279852819
linux user number: 307850                 GPG ID: 5F88735E
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