Re: 2.5.64-mm6: oops in elv_remove_request

Jens Axboe
2003-03-14T17:56:28Z

On Fri, Mar 14 2003, Jeremy Fitzhardinge wrote:
> On Fri, 2003-03-14 at 03:37, Jens Axboe wrote:
> > Can you send me the output of -prcap?
>
> # cdrecord -prcap
> Cdrecord 2.01a05 (i686-pc-linux-gnu) Copyright (C) 1995-2002 J?rg Schilling
> scsidev: '/dev/hdc'
> devname: '/dev/hdc'
> scsibus: -2 target: -2 lun: -2
> Warning: Open by 'devname' is unintentional and not supported.
> Linux sg driver version: 3.5.27
> Using libscg version 'schily-0.7'
> Device type : Removable CD-ROM
> Version : 2
> Response Format: 2
> Capabilities :
> Vendor_info : 'PLEXTOR '
> Identifikation : 'CD-R PX-W4824A'
> Revision : '1.04'
> Device seems to be: Generic mmc CD-RW.
>
> Drive capabilities, per MMC-3 page 2A:
>
> Does read CD-R media
> Does write CD-R media
> Does read CD-RW media
> Does write CD-RW media
> Does not read DVD-ROM media
> Does not read DVD-R media
> Does not write DVD-R media
> Does not read DVD-RAM media
> Does not write DVD-RAM media
> Does support test writing
>
> Does read Mode 2 Form 1 blocks
> Does read Mode 2 Form 2 blocks
> Does read digital audio blocks
> Does restart non-streamed digital audio reads accurately
> Does support Buffer-Underrun-Free recording
> Does read multi-session CDs
> Does read fixed-packet CD media using Method 2
> Does not read CD bar code
> Does read R-W subcode information
> Does return R-W subcode de-interleaved and error-corrected
> Does read raw P-W subcode data from lead in
> Does return CD media catalog number
> Does return CD ISRC information
> Does support C2 error pointers
> Does deliver composite A/V data
>
> Does play audio CDs
> Number of volume control levels: 256
> Does support individual volume control setting for each channel
> Does support independent mute setting for each channel
> Does not support digital output on port 1
> Does not support digital output on port 2
>
> Loading mechanism type: tray
> Does support ejection of CD via START/STOP command
> Does not lock media on power up via prevent jumper
> Does allow media to be locked in the drive via PREVENT/ALLOW command
> Is not currently in a media-locked state
> Does not support changing side of disk
> Does not have load-empty-slot-in-changer feature
> Does not support Individual Disk Present feature
>
> Maximum read speed: 7056 kB/s (CD 40x, DVD 5x)
> Current read speed: 7056 kB/s (CD 40x, DVD 5x)
> Maximum write speed: 8467 kB/s (CD 48x, DVD 6x)
> Current write speed: 8467 kB/s (CD 48x, DVD 6x)
> Rotational control selected: CLV/PCAV
> Buffer size in KB: 4096
> Copy management revision supported: 0
> Number of supported write speeds: 8
> Write speed # 0: 8467 kB/s CLV/PCAV (CD 48x, DVD 6x)
> Write speed # 1: 7056 kB/s CLV/PCAV (CD 40x, DVD 5x)
> Write speed # 2: 5645 kB/s CLV/PCAV (CD 32x, DVD 4x)
> Write speed # 3: 4234 kB/s CLV/PCAV (CD 24x, DVD 3x)
> Write speed # 4: 3528 kB/s CLV/PCAV (CD 20x, DVD 2x)
> Write speed # 5: 2822 kB/s CLV/PCAV (CD 16x, DVD 2x)
> Write speed # 6: 1411 kB/s CLV/PCAV (CD 8x, DVD 1x)
> Write speed # 7: 706 kB/s CLV/PCAV (CD 4x, DVD 0x)
>
>
> But... When I first ran -checkdrive this morning, it gave me good
> results:
>
> # cdrecord -checkdrive
> Cdrecord 2.01a05 (i686-pc-linux-gnu) Copyright (C) 1995-2002 J?rg Schilling
> scsidev: '/dev/hdc'
> devname: '/dev/hdc'
> scsibus: -2 target: -2 lun: -2
> Warning: Open by 'devname' is unintentional and not supported.
> Linux sg driver version: 3.5.27
> Using libscg version 'schily-0.7'
> Device type : Removable CD-ROM
> Version : 2
> Response Format: 2
> Capabilities :
> Vendor_info : 'PLEXTOR '
> Identifikation : 'CD-R PX-W4824A'
> Revision : '1.04'
> Device seems to be: Generic mmc CD-RW.
> Using generic SCSI-3/mmc CD-R driver (mmc_cdr).
> Driver flags : MMC-3 SWABAUDIO BURNFREE VARIREC
> Supported modes: TAO PACKET SAO SAO/R96P SAO/R96R RAW/R16 RAW/R96P RAW/R96R
>
> But immediately afterwards:
>
> # cdrecord -checkdrive
> Cdrecord 2.01a05 (i686-pc-linux-gnu) Copyright (C) 1995-2002 J?rg Schilling
> scsidev: '/dev/hdc'
> devname: '/dev/hdc'
> scsibus: -2 target: -2 lun: -2
> Warning: Open by 'devname' is unintentional and not supported.
> Linux sg driver version: 3.5.27
> Using libscg version 'schily-0.7'
> Device type : Removable CD-ROM
> Version : 0
> Response Format: 1
> Vendor_info : 'PLEXTOR '
> Identifikation : 'CD-R PX-W4824A'
> Revision : '1.04'
> Device seems to be: Generic mmc CD-RW.
> Using generic SCSI-3/mmc CD-R driver (mmc_cdr).
> Driver flags : MMC-3 SWABAUDIO BURNFREE VARIREC
> Supported modes:
>
> Ejecting and reinserting the disc seems to restore things:

Really weird, I can't reproduce here at all. My drive gives the correct
result no matter if it's empty or loaded. Results are repeatable, too.
DMA or PIO, didn't matter.

> Notice the "version" and "response format" fields have changed.

Yeah, something is really screwed. Hmmm, let spend a bit of time with
this problem...

--
Jens Axboe