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April 1, 2011

BUG: ATA Pass-Through BROKEN, bus-trace attached

Forums: 

Bug: Low 28 bits of LBA address to drive after DMA completion (read/write), following the interrupt to the kernel, status is read from the drive with the updated LBA address. The 28 lower bits are then transposed into the NEXT drive commands upper 28bits.

Confirmed: smartmon/sgtools using a Finisar protocol analyzer.

When: Only occurs when using systems whos BIOS is set into Legacy (or ATA/IDE) modes. (Does NOT occur when using AHCI bios mode).

See attached image to see what occured when running SG tools to read the SMART log (command 0x2F)... It becomes very obvious that the ATA Pass-Through driver's actual data becomes over-written with the previous commands LBA address.

Click Here!