Tuesday 12 January 2016

Acer V3-372 SSD Interference Wireless Mouse

I noticed that plugging the usb mouse receiver on the right side USB slots causes the following ATA errors:
[    9.998225] ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300)[   10.001522] ata1.00: configured for UDMA/100[   10.002694] ata1: EH complete[   10.046132] ata1: limiting SATA link speed to 3.0 Gbps[   10.047274] ata1.00: exception Emask 0x10 SAct 0x700 SErr 0x280100 action 0x6 frozen[   10.048415] ata1.00: irq_stat 0x08000000, interface fatal error[   10.049557] ata1: SError: { UnrecovData 10B8B BadCRC }[   10.050707] ata1.00: failed command: READ FPDMA QUEUED[   10.051842] ata1.00: cmd 60/80:40:80:f8:3a/01:00:1c:00:00/40 tag 8 ncq 196608 in                        res 50/00:50:20:f8:3a/00:00:1c:00:00/40 Emask 0x10 (ATA bus error)[   10.054118] ata1.00: status: { DRDY }[   10.055250] ata1.00: failed command: READ FPDMA QUEUED[   10.056376] ata1.00: cmd 60/38:48:40:f8:3a/00:00:1c:00:00/40 tag 9 ncq 28672 in                        res 50/00:50:20:f8:3a/00:00:1c:00:00/40 Emask 0x10 (ATA bus error)[   10.058647] ata1.00: status: { DRDY }[   10.059759] ata1.00: failed command: READ FPDMA QUEUED[   10.060883] ata1.00: cmd 60/18:50:20:f8:3a/00:00:1c:00:00/40 tag 10 ncq 12288 in                        res 50/00:50:20:f8:3a/00:00:1c:00:00/40 Emask 0x10 (ATA bus error)[   10.063158] ata1.00: status: { DRDY }[   10.064277] ata1: hard resetting link[   10.382466] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 320)

Re-locating it to the left side solves it but ties up a USB3.0 slot. I will see if it is possible to shield the SSD.

Monday 11 January 2016

Skylake bug confirmed

Mersenne Prime search has found a reproducible way to hang the CPU. Henk_NL writes:

The fatal combination seems to be:

- Skylake AND
- hyperthreading AND
- CpuSupportsFMA3=0. (only needed if you use the latest version of prime95, since previous version stem from before the introduction use FMA3 anyway)

There are people contemplating writing a piece of software based on prime95 that will simplify freezing the Skylake based on just a few instructions. Very scary indeed and further analysis of the downloadable code is required

https://communities.intel.com/mobile/mobile-access.jspa#jive-content?content=%2Fapi%2Fcore%2Fv3%2Fcontents%2F524553

Hopefully a microcode update will be issued soon.

Friday 1 January 2016

Acer V3-372 Skylake Instability RC6

I have been able to consistently reproduce a GPU hang by playing Portal 2 under Linux. The game starts fine and you can play the first level until you sleep and then it crashes.

The fact that the crash occurs when the graphics are simple lead me to suspect that it could be a power-state issue and so I tried again this time disabling RC6 power-states.

Sure enough, I was able to play beyond this point. I guess it will be a case of waiting until the bugs are all fixed, which could take some time.

Although permanently disabling RC6 could be a workaround, it isn't appealing due to the reduced battery life. Also under the 4.4.0-rc6 kernel, the gpu hangs are more infrequent and no longer seem to lock up the entire system, so for the moment, I leave RC6 enabled.