Re: Re: Is controlling DVD speeds via SET_STREAMING supported?

From: Jens Axboe <axboe@suse.de>
To: Thomas Fritzsche <tf@noto.de>
Cc: linux-kernel@vger.kernel.org, david@2gen.com
Subject: Re: Re: Is controlling DVD speeds via SET_STREAMING supported?
Date: Thu, 25 Nov 2004 09:04:51 +0100	[thread overview]
Message-ID: <20041125080451.GE10233@suse.de> (raw)
In-Reply-To: <33356.192.168.0.2.1101334593.squirrel@192.168.0.10>

On Wed, Nov 24 2004, Thomas Fritzsche wrote:
>  /* SET STREAMING command */
>   cgc.cmd[0] = 0xb6;
>  /* 28 byte parameter list length */
>   cgc.cmd[10] = 28;
> 
>   cgc.sense = &sense;
>   cgc.buffer = buffer;
>   cgc.buflen = sizeof(buffer);
>   cgc.data_direction = CGC_DATA_WRITE;
> 
>   buffer[8] = 0xff;
>   buffer[9] = 0xff;
>   buffer[10] = 0xff;
>   buffer[11] = 0xff;
> 
>   buffer[15] = 177*speed;
>   buffer[18] = 0x03;
>   buffer[19] = 0xE8;

I should have read this more closely... You need to fill the speed
fields correctly:

	unsigned long read_size = 177 * speed;

	buffer[12] = (read_size >> 24) & 0xff;
	buffer[13] = (read_size >> 16) & 0xff;
	buffer[14] = (read_size >>  8) & 0xff;
	buffer[15] = read_size & 0xff;

Ditto for write size.

-- 
Jens Axboe