Hi,
Google suggests it may be a common problem with NEC ND-4550A DVD-RW
drives.
First thing: the drive frequently needs a lot of time to recognize the
disc, sometimes more than the usual 30 seconds SCSI timeout. I tried to
"echo 100 > /sys/block/sr0/device/timeout" but it doesn't seem to change
anything, should it? The timeout still occurs after 30 seconds (I'm not
pushing the disc tray manually, the mount pulls it in for me).
ata7.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x6 frozen
sr 6:0:0:0: CDB: Start/Stop Unit: 1b 00 00 00 03 00
ata7.00: cmd a0/00:00:00:00:00/00:00:00:00:00/a0 tag 0
res 40/00:02:00:08:00/00:00:00:00:00/a0 Emask 0x4 (timeout)
ata7.00: status: { DRDY }
ata7: link is slow to respond, please be patient (ready=0)
ata7: device not ready (errno=-16), forcing hardreset
ata7: soft resetting link
ata7.00: FORCE: xfer_mask set to udma33
ata7.00: configured for UDMA/33
ata7: EH complete
sr0: CDROM (ioctl) error, command: Start/Stop Unit 1b 00 00 00 03 00
sr: Sense Key : Aborted Command [current] [descriptor]
sr: Add. Sense: No additional sense information
I'm using the "FORCE" to prevent Linux from downgrading to PIO modes,
they are a performance disaster.
Is there any other way to have a longer command timeout (perhaps while
loading the disc only)?
Second thing: the drive frequently responds to READ_CAPACITY with a zero
(one sector).
sr_cd_check() - for both working and non-working cases:
...
case VENDOR_SCSI3:
cgc.cmd[0] = READ_TOC;
cgc.cmd[8] = 12;
cgc.cmd[9] = 0x40;
cgc.buffer = buffer;
cgc.buflen = 12;
cgc.quiet = 1;
cgc.data_direction = DMA_FROM_DEVICE;
cgc.timeout = VENDOR_TIMEOUT;
rc = sr_do_ioctl(cd, &cgc);
At this point rc = 0, buffer = 00 0A 01 01 00 14 01 00 00 00 00 00.
Then get_sectorsize() does READ_CAPACITY which completes without errors.
Sometimes the scsi_execute_req() returns e.g.:
buffer = 00 23 01 6F 00 00 08 00
which results in set_capacity(9176512)
and sometimes the return value is:
buffer = 00 00 00 00 00 00 08 00
which sets the media size to 2048 bytes (cat /sys/block/sr0/size returns
4, the kernel "attempts to access beyond end of device" etc).
I'm aware of http://bugzilla.kernel.org/show_bug.cgi?id=9668 and that
the fix for it is in the tree, but it doesn't really fix this issue for
me.
The following work-around makes the disc readable:
if (!cdrom_get_last_written(&cd->cdi, &last_written))
cd->capacity = max_t(long, cd->capacity, last_written);
+ if (cd->capacity == 1)
+ cd->capacity = 50 /* GiB */ * 1024 * 1024 / 2;
+
sector_size = (buffer[4] << 24) |
(buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
Though I'm sure there is much better way to fix it.
When the drive can't read the medium size, dvd+rw-mediainfo prints:
INQUIRY: [_NEC ][DVD_RW ND-4550A ][1.09]
GET [CURRENT] CONFIGURATION:
Mounted Media: 14h, DVD-RW Sequential
Media ID: MCC 03RG20
Current Write Speed: 6.1x1385=8467KB/s
Write Speed #0: 6.1x1385=8467KB/s
Write Speed #1: 5.1x1385=7056KB/s
Write Speed #2: 4.1x1385=5645KB/s
Write Speed #3: 3.1x1385=4234KB/s
Write Speed #4: 2.0x1385=2822KB/s
Write Speed #5: 1.0x1385=1411KB/s
GET [CURRENT] PERFORMANCE:
Write Performance: 1.0x1385=1385KB/s@[0 -> 2297888]
:-( empty GET PERFORMACE descriptor
READ DVD STRUCTURE[#10h]:
Media Book Type: 00h, DVD-ROM book [revision 0]
Legacy lead-out at: 2298496*2KB=4707319808
READ DVD STRUCTURE[#0h]:
Media Book Type: 25h, DVD-R book [revision 5]
Last border-out at: 2045*2KB=4188160
READ DISC INFORMATION:
Disc status: complete
Number of Sessions: 1
State of Last Session: complete
Number of Tracks: 1
READ FORMAT CAPACITIES:
formatted: 0*2048=0
00h(800): 2297888*2048=4706074624
10h(10): 2297888*2048=4706074624
15h(10): 2297888*2048=4706074624
READ TRACK INFORMATION[#1]:
Track State: complete,damaged
Track Start Address: 0*2KB
Free Blocks: 0*2KB
Track Size: 1*2KB
FABRICATED TOC:
Track#1 : 14@0
Track#AA : 14@2297888
Multi-session Info: #1@0
READ CAPACITY: 0*2048=0
When the medium size is detected the output differs (the same disc, it
works and doesn't work randomly):
- Mounted Media: 14h, DVD-RW Sequential
+ Mounted Media: 11h, DVD-R Sequential
- Write Performance: 1.0x1385=1385KB/s@[0 -> 2297888]
-:-( empty GET PERFORMACE descriptor
+ Write Performance: 6.6x1385=9141KB/s@0 -> 16.0x1385=22160KB/s@2294128
+ Speed Descriptor#0: 03/2294128 R@xxxxxxxxx=22160KB/s W@xxxxxxxxx=22160KB/s
+ Speed Descriptor#1: 03/2294128 R@xxxxxxxxx=16620KB/s W@xxxxxxxxx=16620KB/s
+ Speed Descriptor#2: 00/2294128 R@xxxxxxxx=11080KB/s W@xxxxxxxx=11080KB/s
+ Speed Descriptor#3: 00/2294128 R@xxxxxxxx=11080KB/s W@xxxxxxxx=8310KB/s
+ Speed Descriptor#4: 00/2294128 R@xxxxxxxx=6925KB/s W@xxxxxxxx=5540KB/s
+ Speed Descriptor#5: 00/2294128 R@xxxxxxxx=6925KB/s W@xxxxxxxx=2770KB/s
-READ FORMAT CAPACITIES:
- formatted: 0*2048=0
- 00h(800): 2297888*2048=4706074624
- 10h(10): 2297888*2048=4706074624
- 15h(10): 2297888*2048=4706074624
READ TRACK INFORMATION[#1]:
- Track State: complete,damaged
+ Track State: complete incremental
Track Start Address: 0*2KB
Free Blocks: 0*2KB
- Track Size: 1*2KB
+ Track Size: 2294128*2KB
+ Last Recorded Address: 2294127*2KB
FABRICATED TOC:
Track#1 : 14@0
- Track#AA : 14@2297888
+ Track#AA : 14@2294128
Multi-session Info: #1@0
-READ CAPACITY: 0*2048=0
+READ CAPACITY: 2294128*2048=4698374144
Any ideas?
Linux v2.6.37.2, x86-64 SMP, the discs are Verbatim DVD-R single layer.
With the "50 GiB" patch applied and without triggering the SCSI timeout
(after the disc is inserted - i.e. inserting by hand and waiting for the
drive to recognize the disc before trying to mount it) the discs are
perfectly readable. Also, a different drive (such as old DVD-ROM/CD-RW
Toshiba "combo") reads them without problems.
This is a PATA drive connected to JMicron JMB363 PATA port.
--
Krzysztof Halasa
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