Comment 38 for bug 1449005

So I have an 840 EVO, and have ncq enabled and am running the latest firmware. I do not have the discard option in fstab, but instead run fstrim weekly as is the default in ubuntu. Everything seems to be functioning fine for me.

It's entirely possible that something else is at play here. Perhaps your sectors had electrically degraded to the point of data loss, and the firmware update simply marked them bad for lack of being refreshed.

[ 1.108071] ata5: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[ 1.108119] ata6: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[ 1.108155] ata2: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
[ 1.108180] ata3: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
[ 1.108206] ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
[ 1.108234] ata4: SATA link down (SStatus 0 SControl 300)
[ 1.110025] ata2.00: supports DRM functions and may not be fully accessible
[ 1.110107] ata2.00: ATA-9: Samsung SSD 840 EVO 500GB, EXT0DB6Q, max UDMA/133
[ 1.110110] ata2.00: 976773168 sectors, multi 1: LBA48 NCQ (depth 31/32), AA
[ 1.110293] ata2.00: supports DRM functions and may not be fully accessible
[ 1.110336] ata2.00: configured for UDMA/133