Posted by: Anonymous Coward
on February 15, 2005 02:24 AM
In response to point #1:
The issue with the CD-ROM drive actually *was* the manufacturer's fault. LG decided to have their CD-ROM drive use a standard ATAPI command in a non-standard way. If the drive follows the ATAPI standard (like these claimed to), the command only does anything on a DVD-RW or CD-RW drive. In the case of these LG CD-ROM drives, they decided to use this command to *flash the drive's firmware*!
As for why RedHat and Debian didn't have a problem with the LG drives? Simple. Mandrake's release came before theirs, so by the time they released their distributions, the kernel drivers had been patched to *never* send that command to those types of drives, *and* LG had released new firmware which no longer suffered from the problem.
Here's the details of the issue: "A problem with LG CD-ROM drives was discovered that the kernel shipped with Mandrakelinux 9.2 triggered. This problem was that the kernel would send a FLUSH_CACHE command to the LG CD-ROM drive which would make the drive inoperable by overwriting its firmware. This is because some LG CD-ROM drives are not compliant with the ATAPI specification. The specification does not require an implementation of the FLUSH_CACHE command in the driver, and returning an error (or doing nothing) would have been the correct behaviour for the drive. Likewise, reusing a command is against the specification and LG has reused the FLUSH_CACHE command to modify the firmware of the drive, but they are unwilling to disclose exactly what the command does. This FLUSH_CACHE command is supposed to be supported only by CD-RW or DVD-RW devices; the LG-based CD-ROM devices are understanding this command as the UPLOAD_FIRMWARE command."
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Re:the top of the top!
Posted by: Anonymous Coward on February 15, 2005 02:24 AMThe issue with the CD-ROM drive actually *was* the manufacturer's fault. LG decided to have their CD-ROM drive use a standard ATAPI command in a non-standard way. If the drive follows the ATAPI standard (like these claimed to), the command only does anything on a DVD-RW or CD-RW drive. In the case of these LG CD-ROM drives, they decided to use this command to *flash the drive's firmware*!
As for why RedHat and Debian didn't have a problem with the LG drives? Simple. Mandrake's release came before theirs, so by the time they released their distributions, the kernel drivers had been patched to *never* send that command to those types of drives, *and* LG had released new firmware which no longer suffered from the problem.
Here's the details of the issue:
"A problem with LG CD-ROM drives was discovered that the kernel shipped with Mandrakelinux 9.2 triggered. This problem was that the kernel would send a FLUSH_CACHE command to the LG CD-ROM drive which would make the drive inoperable by overwriting its firmware. This is because some LG CD-ROM drives are not compliant with the ATAPI specification. The specification does not require an implementation of the FLUSH_CACHE command in the driver, and returning an error (or doing nothing) would have been the correct behaviour for the drive. Likewise, reusing a command is against the specification and LG has reused the FLUSH_CACHE command to modify the firmware of the drive, but they are unwilling to disclose exactly what the command does. This FLUSH_CACHE command is supposed to be supported only by CD-RW or DVD-RW devices; the LG-based CD-ROM devices are understanding this command as the UPLOAD_FIRMWARE command."
Check this page for the full story: http://www.mandrakelinux.com/en/lgerrata.php3
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