Greetings,

I straced both a good and a bad kernel (good being .git with attached
revert patch applied) and filtered/diffed/merged the output.  Scroll
down to "HERE" to see the problem (resid).

I'm poking around, but not having much luck.

--- good	2008-02-26 09:11:08.000000000 +0100
+++ bad	2008-02-26 09:03:44.000000000 +0100
@@ -1,48 +1,44 @@
 open("/dev/sr0", O_RDWR|O_NONBLOCK) = 3
 fcntl64(3, F_GETFL)         = 0x8802 (flags O_RDWR|O_NONBLOCK|O_LARGEFILE)
 fcntl64(3, F_SETFL, O_RDWR|O_LARGEFILE) = 0
-ioctl(3, CDROMAUDIOBUFSIZ or SCSI_IOCTL_GET_IDLUN, 0xaf8d9194) = 0
-ioctl(3, SCSI_IOCTL_GET_BUS_NUMBER, 0xaf8d9190) = 0
-ioctl(3, SG_GET_VERSION_NUM, 0xaf8d9198) = 0
+ioctl(3, CDROMAUDIOBUFSIZ or SCSI_IOCTL_GET_IDLUN, 0xafa1a2d4) = 0
+ioctl(3, SCSI_IOCTL_GET_BUS_NUMBER, 0xafa1a2d0) = 0
+ioctl(3, SG_GET_VERSION_NUM, 0xafa1a2d8) = 0
 write(2, "Linux sg driver version: 3.5.27\n", 32Linux sg driver version: 3.5.27
 ) = 32
-ioctl(3, CDROMAUDIOBUFSIZ or SCSI_IOCTL_GET_IDLUN, 0xaf8d9134) = 0
-ioctl(3, SCSI_IOCTL_GET_BUS_NUMBER, 0xaf8d9130) = 0
-ioctl(3, SG_SET_TIMEOUT, 0xaf8d9030) = 0
-fstat64(3, {st_dev=makedev(0, 13), st_ino=4758, st_mode=S_IFBLK|0640, st_nlink=1, st_uid=0, st_gid=6, st_blksize=4096, st_blocks=0, st_rdev=makedev(11, 0), st_atime=2008/02/26-08:45:17, st_mtime=2008/02/26-08:45:17, st_ctime=2008/02/26-08:45:17}) = 0
+ioctl(3, CDROMAUDIOBUFSIZ or SCSI_IOCTL_GET_IDLUN, 0xafa1a274) = 0
+ioctl(3, SCSI_IOCTL_GET_BUS_NUMBER, 0xafa1a270) = 0
+ioctl(3, SG_SET_TIMEOUT, 0xafa1a170) = 0
+fstat64(3, {st_dev=makedev(0, 13), st_ino=4572, st_mode=S_IFBLK|0640, st_nlink=1, st_uid=0, st_gid=6, st_blksize=4096, st_blocks=0, st_rdev=makedev(11, 0), st_atime=2008/02/26-09:36:43, st_mtime=2008/02/26-09:36:43, st_ctime=2008/02/26-09:36:43}) = 0
 geteuid32()                 = 0
 getuid32()                  = 0
 write(1, "Using libscg version \'schily-0.9"..., 35) = 35
 write(1, "Driveropts: \'burnfree\'\n", 23) = 23
-ioctl(3, SG_GET_RESERVED_SIZE, 0xaf8d93d4) = 0
-ioctl(3, SG_GET_RESERVED_SIZE, 0xaf8d93d8) = 0
-ioctl(3, SG_GET_PACK_ID, 0xaf8d93d0) = -1 ENOTTY (Inappropriate ioctl for device)
+ioctl(3, SG_GET_RESERVED_SIZE, 0xafa1a514) = 0
+ioctl(3, SG_GET_RESERVED_SIZE, 0xafa1a518) = 0
+ioctl(3, SG_GET_PACK_ID, 0xafa1a510) = -1 ENOTTY (Inappropriate ioctl for device)
 write(2, "SCSI buffer size: 64512\n", 24SCSI buffer size: 64512
 ) = 24
-ioctl(3, SG_GET_RESERVED_SIZE, 0xaf8d93b4) = 0
-ioctl(3, SG_GET_RESERVED_SIZE, 0xaf8d93b8) = 0
-ioctl(3, SG_GET_PACK_ID, 0xaf8d93b0) = -1 ENOTTY (Inappropriate ioctl for device)
-brk(0x9520000)              = 0x9520000
-ioctl(3, SG_EMULATED_HOST, 0xaf8d93ec) = 0
+ioctl(3, SG_GET_RESERVED_SIZE, 0xafa1a4f4) = 0
+ioctl(3, SG_GET_RESERVED_SIZE, 0xafa1a4f8) = 0
+ioctl(3, SG_GET_PACK_ID, 0xafa1a4f0) = -1 ENOTTY (Inappropriate ioctl for device)
+brk(0x9fa8000)              = 0x9fa8000
+ioctl(3, SG_EMULATED_HOST, 0xafa1a52c) = 0
 
HERE

write(1, "atapi: 1\n", 9)   = 9
 ioctl(3, SG_IO, {'S', SG_DXFER_NONE, cmd[6]=[00, 00, 00, 00, 00, 00], mx_sb_len=16, iovec_count=0, dxfer_len=0, timeout=200000, flags=0x1, status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=0, duration=1, info=0}) = 0
 ioctl(3, SG_IO, {'S', SG_DXFER_NONE, cmd[6]=[00, 00, 00, 00, 00, 00], mx_sb_len=16, iovec_count=0, dxfer_len=0, timeout=200000, flags=0x1, status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=0, duration=1, info=0}) = 0
-ioctl(3, SG_IO, {'S', SG_DXFER_FROM_DEV, cmd[6]=[12, 00, 00, 00, 24, 00], mx_sb_len=16, iovec_count=0, dxfer_len=36, timeout=200000, flags=0x1, data[36]=["\5\200\0052[\0\0\0BENQ    DVD DD DW1625   "...], status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=0, duration=1, info=0}) = 0
+ioctl(3, SG_IO, {'S', SG_DXFER_FROM_DEV, cmd[6]=[12, 00, 00, 00, 24, 00], mx_sb_len=16, iovec_count=0, dxfer_len=36, timeout=200000, flags=0x1, data[36]=["\5\200\0052[\0\0\0BENQ    DVD DD DW1625   "...], status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=36, duration=2, info=0}) = 0
 ioctl(3, SG_IO, {'S', SG_DXFER_NONE, cmd[6]=[00, 00, 00, 00, 00, 00], mx_sb_len=16, iovec_count=0, dxfer_len=0, timeout=200000, flags=0x1, status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=0, duration=1, info=0}) = 0
-ioctl(3, SG_IO, {'S', SG_DXFER_FROM_DEV, cmd[10]=[5a, 00, 3f, 00, 00, 00, 00, 00, 08, 00], mx_sb_len=16, iovec_count=0, dxfer_len=8, timeout=200000, flags=0x1, data[8]=["\1\36\21\0\0\0\0\0"], status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=0, duration=6, info=0}) = 0
+ioctl(3, SG_IO, {'S', SG_DXFER_FROM_DEV, cmd[10]=[5a, 00, 3f, 00, 00, 00, 00, 00, 08, 00], mx_sb_len=16, iovec_count=0, dxfer_len=8, timeout=200000, flags=0x1, data[8]=["\1\36\21\0\0\0\0\0"], status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=8, duration=4, info=0}) = 0
 ioctl(3, SG_IO, {'S', SG_DXFER_NONE, cmd[6]=[00, 00, 00, 00, 00, 00], mx_sb_len=16, iovec_count=0, dxfer_len=0, timeout=200000, flags=0x1, status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=0, duration=1, info=0}) = 0
-ioctl(3, SG_IO, {'S', SG_DXFER_FROM_DEV, cmd[10]=[5a, 00, 2a, 00, 00, 00, 00, 00, 02, 00], mx_sb_len=16, iovec_count=0, dxfer_len=2, timeout=200000, flags=0x1, data[2]=["\0>"], status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=0, duration=2, info=0}) = 0
+ioctl(3, SG_IO, {'S', SG_DXFER_FROM_DEV, cmd[10]=[5a, 00, 2a, 00, 00, 00, 00, 00, 02, 00], mx_sb_len=16, iovec_count=0, dxfer_len=2, timeout=200000, flags=0x1, data[2]=["\0>"], status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=2, duration=3, info=0}) = 0
-ioctl(3, SG_IO, {'S', SG_DXFER_NONE, cmd[6]=[00, 00, 00, 00, 00, 00], mx_sb_len=16, iovec_count=0, dxfer_len=0, timeout=200000, flags=0x1, status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=0, duration=1, info=0}) = 0
+ioctl(3, SG_IO, {'S', SG_DXFER_NONE, cmd[6]=[00, 00, 00, 00, 00, 00], mx_sb_len=16, iovec_count=0, dxfer_len=0, timeout=200000, flags=0x1, status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=0, duration=2, info=0}) = 0
-ioctl(3, SG_IO, {'S', SG_DXFER_FROM_DEV, cmd[10]=[5a, 00, 2a, 00, 00, 00, 00, 00, 40, 00], mx_sb_len=16, iovec_count=0, dxfer_len=64, timeout=200000, flags=0x1, data[64]=["\0>\21\0\0\0\0\0*6\37\27\365g) \33\220\0\2\10\0\33\220\0\0\33\220\33\220\0\1"...], status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=0, duration=3, info=0}) = 0
+ioctl(3, SG_IO, {'S', SG_DXFER_FROM_DEV, cmd[10]=[5a, 00, 2a, 00, 00, 00, 00, 00, 40, 00], mx_sb_len=16, iovec_count=0, dxfer_len=64, timeout=200000, flags=0x1, data[64]=["\0>\21\0\0\0\0\0*6\37\27\365g) \33\220\0\2\10\0\33\220\0\0\33\220\33\220\0\1"...], status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=64, duration=3, info=0}) = 0
-ioctl(3, SG_IO, {'S', SG_DXFER_NONE, cmd[6]=[00, 00, 00, 00, 00, 00], mx_sb_len=16, iovec_count=0, dxfer_len=0, timeout=200000, flags=0x1, status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=0, duration=1, info=0}) = 0
+ioctl(3, SG_IO, {'S', SG_DXFER_NONE, cmd[6]=[00, 00, 00, 00, 00, 00], mx_sb_len=16, iovec_count=0, dxfer_len=0, timeout=200000, flags=0x1, status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=0, duration=1, info=0}) = 0
-ioctl(3, SG_IO, {'S', SG_DXFER_FROM_DEV, cmd[10]=[5a, 00, 2a, 00, 00, 00, 00, 00, 40, 00], mx_sb_len=16, iovec_count=0, dxfer_len=64, timeout=200000, flags=0x1, data[64]=["\0>\21\0\0\0\0\0*6\37\27\365g) \33\220\0\2\10\0\33\220\0\0\33\220\33\220\0\1"...], status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=0, duration=3, info=0}) = 0
+ioctl(3, SG_IO, {'S', SG_DXFER_FROM_DEV, cmd[10]=[5a, 00, 2a, 00, 00, 00, 00, 00, 0a, 00], mx_sb_len=16, iovec_count=0, dxfer_len=10, timeout=200000, flags=0x1, data[10]=["\0>\21\0\0\0\0\0*6"], status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=10, duration=3, info=0}) = 0
-ioctl(3, SG_IO, {'S', SG_DXFER_NONE, cmd[6]=[00, 00, 00, 00, 00, 00], mx_sb_len=16, iovec_count=0, dxfer_len=0, timeout=200000, flags=0x1, status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=0, duration=1, info=0}) = 0
+ioctl(3, SG_IO, {'S', SG_DXFER_NONE, cmd[6]=[00, 00, 00, 00, 00, 00], mx_sb_len=16, iovec_count=0, dxfer_len=0, timeout=200000, flags=0x1, status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=0, duration=0, info=0}) = 0
-
-write(1, "Device type    : Removable CD-RO"..., 34) = 34
-write(1, "Version        : 5\n", 19) = 19
-write(1, "Response Format: 2\n", 19) = 19
-write(1, "Capabilities   : \n", 18) = 18
-write(1, "Vendor_info    : \'BENQ    \'\n", 28) = 28
-write(1, "Identifikation : \'DVD DD DW1625 "..., 36) = 36
-write(1, "Revision       : \'BBIA\'\n", 24) = 24
-write(1, "Device seems to be: Generic mmc2"..., 55) = 55
+ioctl(3, SG_IO, {'S', SG_DXFER_FROM_DEV, cmd[10]=[5a, 00, 2a, 00, 00, 00, 00, 00, 40, 00], mx_sb_len=16, iovec_count=0, dxfer_len=64, timeout=200000, flags=0x1, data[64]=["\0>\21\0\0\0\0\0*6\37\27\365g) \33\220\0\2\10\0\33\220\0\0\33\220\33\220\0\1"...], status=00, masked_status=00, sb[0]=[], host_status=0, driver_status=0, resid=64, duration=3, info=0}) = 0
+write(2, "/usr/bin/cdrecord: Warning: cont"..., 80/usr/bin/cdrecord: Warning: controller returns zero sized CD capabilities page.
+) = 80
+write(2, "/usr/bin/cdrecord: Warning: cont"..., 91/usr/bin/cdrecord: Warning: controller returns wrong page 0 for CD capabilities page (2A).
+) = 91