tree 5c563b30ec17293cd52d8a44c90e5951d36e3242
parent 47ee9108c1dcca434f479e9e520789d2a2ab7917
author Prarit Bhargava <prarit@redhat.com> 1336482482 -0400
committer Jeff Garzik <jgarzik@redhat.com> 1337716934 -0400

[libata] Add " 2GB ATA Flash Disk"/"ADMA428M" to DMA blacklist

A user has several systems with a couple of models of flash disks with IDE
connectors.  These disks work fine in 2.6.18-ish kernels but corrupt data on
new kernels.

The difference appears to be with the default I/O method used by the IDE
controller driver between the kernels.  In the older kernels, the
configuration is very conservative and the driver stays in PIO mode.  With
new kernels, the ata driver (pata_serverworks) attempts to use UDMA/66
which the drive claims to support.  This mode, however, does not appear to
work in DMA mode.  The drive does work correctly and no corruption is
seen if the kernel parameter "libata.force=5:pio0,6:pio0" is used to force
the driver to use PIO instead of DMA mode.

Blacklist these drives.  Unfortunately the model name of the drive is very
generic, " 2GB ATA Flash Disk", but the revision is specific, "ADMA428M".

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>