2005-09-12 12:12:33

by Mathieu Fluhr

[permalink] [raw]
Subject: 2.6.13 brings buffer underruns when burning DVDs at high speeds (16x)

Hello all,

It seems that something has been broken when passing from 2.6.12 to
2.6.13 regarding the SCSI burning engine. When burning a DVD at 16x
(with ide-cd SEND_PACKET command, or with the SG interface, no matter
the driver used), you get tons of buffer underruns. This was not
appearing in 2.6.12.

I would suspect something in the block devices driver, but I am not
really sure... and I did not have enough time yet to look deeply in the
source code ;-)

Best Regards,
Mathieu


2005-09-12 18:09:39

by Mathieu Fluhr

[permalink] [raw]
Subject: Re: 2.6.13 brings buffer underruns when burning DVDs at high speeds (16x)

Hummm Okay. After making some ugly changes (I basically reverted all
the /drivers/block subdir to version 2.6.12.6), I still have buffer
underruns.

Does anyone know where it could come from ? I would say that I am a
little bit stuck now. I am quite sure that it is also not comming from
the devices driver (ide-cd, usb-storage...) as I tried with different
devices on different ports (mostly IDE and emulated SCSI via USB) with
the same result.

Note: This is also happening with k3b ;-)

On Mon, 2005-09-12 at 14:11 +0200, Mathieu Fluhr wrote:
> Hello all,
>
> It seems that something has been broken when passing from 2.6.12 to
> 2.6.13 regarding the SCSI burning engine. When burning a DVD at 16x
> (with ide-cd SEND_PACKET command, or with the SG interface, no matter
> the driver used), you get tons of buffer underruns. This was not
> appearing in 2.6.12.
>
> I would suspect something in the block devices driver, but I am not
> really sure... and I did not have enough time yet to look deeply in the
> source code ;-)
>
> Best Regards,
> Mathieu
>
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2005-09-13 16:13:33

by Alexey Dobriyan

[permalink] [raw]
Subject: Re: 2.6.13 brings buffer underruns when burning DVDs at high speeds (16x)

On Mon, Sep 12, 2005 at 02:11:53PM +0200, Mathieu Fluhr wrote:
> It seems that something has been broken when passing from 2.6.12 to
> 2.6.13 regarding the SCSI burning engine. When burning a DVD at 16x
> (with ide-cd SEND_PACKET command, or with the SG interface, no matter
> the driver used), you get tons of buffer underruns. This was not
> appearing in 2.6.12.

I've filed a bug at kernel bugzilla, so your report won't be lost. See
http://bugme.osdl.org/show_bug.cgi?id=5242

Please, register at http://bugme.osdl.org/createaccount.cgi and add
yourself to bug's CC list.