>From: Douglas Gilbert <[EMAIL PROTECTED]>
>> There is a fatal bug in the sg driver:
>>
>> it may hang infintely and unkillable in open("/dev/sg1", 2)
>>
>>
>> Repeat: Insert a PCATA CD-Writer in a Sony VAIO notebook and run
>> cdrecord -scanbus.
>>
>> I tried a workaround with alarm()/setjmp()/longjmp() but even signals
>> are not processed
>J�rg,
>Could you supply further information such as which
>linux kernel version? Is the cdwriter SCSI, ATAPI,
>IEE1394, USB-2 ...? Is it likely that there are
>2 (pseudo) scsi devices on that notebook?
As I cannot see any progress with ATAPI within the last 3 years,
I susect that the version does not matter.
It is a vanilla SuSe 7.2 with 2.4.4-4GB kernel.
I am unsure why you ask for the writer interface, I already mentioned it:
PCATA
>Looking at sg_open() the only "wait" done there is
>associated with the exclusive lock and that wait is
>interruptible. sg_open() does call the linux scsi
>mid-level code [scsi_block_when_processing_errors()]
>which could wait forever in non-interruptible state.
>This would imply that the device was continually in
>the "recovering from error" state.
>If you have access to the machine and cdwriter in
>question and the machine is still useable after the
>reported problem, then this command may help find
>where open("/dev/sg1", ...) is hanging inside the
>kernel:
> ps -eo cmd,wchan
It hangs in "scsi_block_when_processing_errors"
>There may also be some information in the /var/log/messages
>file (potentially showing ongoing device resets). If the
>cdwriter is ATAPI and the kernel is in the 2.4 series
>then turning off (or reducing the speed of) DMA may be
>helpful.
There is absolutely nothing in the message files.
I am not sure if you don't know this, but Linux does not support
DMA for PCATA drives. Some people state that this is not true,
but those people could never have tried to use Linux this way.
Unfortunately, Alan Cox is ne of these persons ;-(
If you turn on DMA at the device, Linux will not detect it.
J�rg
EMail:[EMAIL PROTECTED] (home) J�rg Schilling D-13353 Berlin
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