`dd` problem from cdrom

[Colin Leroy <colin@colino.net>]

Hi,

Using 2.6.10 and 2.6.11, trying to use dd from the ide cdrom in my
Ibook G4 fails like this:

[colin@jack /usr/src/linux-2.6.10]$ dd if=/dev/hdc of=/dev/null
dd: reading `/dev/hdc': Input/output error
0+0 records in
0+0 records out
[colin@jack /usr/src/linux-2.6.10]$ dmesg
hdc: command error: status=0x51 { DriveReady SeekComplete Error }
hdc: command error: error=0x54 { AbortedCommand LastFailedSense=0x05 }
ide: failed opcode was: unknown
end_request: I/O error, dev hdc, sector 0
Buffer I/O error on device hdc, logical block 0
hdc: command error: status=0x51 { DriveReady SeekComplete Error }
hdc: command error: error=0x54 { AbortedCommand LastFailedSense=0x05 }
ide: failed opcode was: unknown
end_request: I/O error, dev hdc, sector 8
Buffer I/O error on device hdc, logical block 1
hdc: command error: status=0x51 { DriveReady SeekComplete Error }
hdc: command error: error=0x54 { AbortedCommand LastFailedSense=0x05 }
ide: failed opcode was: unknown
end_request: I/O error, dev hdc, sector 16
Buffer I/O error on device hdc, logical block 2
hdc: command error: status=0x51 { DriveReady SeekComplete Error }
hdc: command error: error=0x54 { AbortedCommand LastFailedSense=0x05 }
ide: failed opcode was: unknown
end_request: I/O error, dev hdc, sector 24
Buffer I/O error on device hdc, logical block 3
hdc: command error: status=0x51 { DriveReady SeekComplete Error }
hdc: command error: error=0x54 { AbortedCommand LastFailedSense=0x05 }
ide: failed opcode was: unknown
end_request: I/O error, dev hdc, sector 32
Buffer I/O error on device hdc, logical block 4
hdc: command error: status=0x51 { DriveReady SeekComplete Error }
hdc: command error: error=0x54 { AbortedCommand LastFailedSense=0x05 }
ide: failed opcode was: unknown
end_request: I/O error, dev hdc, sector 40
Buffer I/O error on device hdc, logical block 5
hdc: command error: status=0x51 { DriveReady SeekComplete Error }
hdc: command error: error=0x54 { AbortedCommand LastFailedSense=0x05 }
ide: failed opcode was: unknown
end_request: I/O error, dev hdc, sector 48
Buffer I/O error on device hdc, logical block 6
hdc: command error: status=0x51 { DriveReady SeekComplete Error }
hdc: command error: error=0x54 { AbortedCommand LastFailedSense=0x05 }
ide: failed opcode was: unknown
end_request: I/O error, dev hdc, sector 56
Buffer I/O error on device hdc, logical block 7
hdc: command error: status=0x51 { DriveReady SeekComplete Error }
hdc: command error: error=0x54 { AbortedCommand LastFailedSense=0x05 }
ide: failed opcode was: unknown
end_request: I/O error, dev hdc, sector 0
Buffer I/O error on device hdc, logical block 0
[colin@jack /usr/src/linux-2.6.10]$ hdparm /dev/hdc

/dev/hdc:
 HDIO_GET_MULTCOUNT failed: Invalid argument
 IO_support   =  0 (default 16-bit)
 unmaskirq    =  1 (on)
 using_dma    =  1 (on)
 keepsettings =  0 (off)
 readonly     =  0 (off)
 readahead    = 256 (on)
 HDIO_GETGEO failed: Invalid argument


I didn't try older kernels yet; Any idea about this? Is it a kernel bug
or a configuration issue? 
-- 
Colin