Message-ID: <3E64EE6A.90208@lemur.sytes.net>
Date: Tue, 04 Mar 2003 13:20:26 -0500
From: Mathias Kretschmer <mathias@lemur.sytes.net>
Reply-To: mathias.kretschmer@verizon.net
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To: linux-kernel@vger.kernel.org
Subject: IDE DVD reading & error handling
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Hello,

Is there a way to optimize the IDE layer to handle DVD
read errors more gracefully ?

Most used DVDs (borrowed from a local library, etc.) seem to have some 
defects. Those cause the IDE layer to get stuck for quite a while, 
interrupting the movie playback. It might be better to just return an 
error for that sector and let the player software continue.

I wonder if it would be possible to tune the IDE layer by i.e.
reducing the number of retries and disabling the controller reset, etc.

I haven't fiddle with the below numbers, yet. Just wondering if that
could improve the situation, or if there are any other tricks that one 
could play here ?

/*
  * Probably not wise to fiddle with these
  */
#define ERROR_MAX       8       /* Max read/write errors per sector */
#define ERROR_RESET     3       /* Reset controller every 4th retry */
#define ERROR_RECAL     1       /* Recalibrate every 2nd retry */

Cheers,

Mathias

PS: Also which DVD ROM do people recommended in general ?
     Which one seems to have a decent error correction scheme
     not just a high read speed?

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