Ноутбук неожиданно зависает

У меня ноутбук Lenovo T540p с Ubuntu 14.04. Я использовал его около 2 недель, и он зависал 4 раза (3 раза с темными экранами и 1 раз с тем же экраном, с которым я работал). После перезагрузки я смог найти некоторые ошибки в файле kern.log (смог найти его в последний раз).

Это последние записи журнала в /var/log/kern.log перед зависанием ноутбука.

May 23 22:12:11 maduranga-ThinkPad-T540p kernel: [44393.522662] ata1: exception Emask 0x50 SAct 0x0 SErr 0x4090800 action 0xe frozen
May 23 22:12:11 maduranga-ThinkPad-T540p kernel: [44393.522672] ata1: irq_stat 0x00400040, connection status changed
May 23 22:12:11 maduranga-ThinkPad-T540p kernel: [44393.522679] ata1: SError: { HostInt PHYRdyChg 10B8B DevExch }
May 23 22:12:11 maduranga-ThinkPad-T540p kernel: [44393.522687] ata1: hard resetting link
May 23 22:12:11 maduranga-ThinkPad-T540p kernel: [44393.522710] ata6: exception Emask 0x50 SAct 0x0 SErr 0x4090800 action 0xe frozen
May 23 22:12:11 maduranga-ThinkPad-T540p kernel: [44393.522718] ata6: irq_stat 0x00400040, connection status changed
May 23 22:12:11 maduranga-ThinkPad-T540p kernel: [44393.522724] ata6: SError: { HostInt PHYRdyChg 10B8B DevExch }
May 23 22:12:11 maduranga-ThinkPad-T540p kernel: [44393.522733] ata6: hard resetting link
May 23 22:12:12 maduranga-ThinkPad-T540p kernel: [44394.246738] ata6: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
May 23 22:12:12 maduranga-ThinkPad-T540p kernel: [44394.246783] ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
May 23 22:12:12 maduranga-ThinkPad-T540p kernel: [44394.247101] ata1.00: ACPI cmd ef/02:00:00:00:00:a0 (SET FEATURES) succeeded
May 23 22:12:12 maduranga-ThinkPad-T540p kernel: [44394.247103] ata1.00: ACPI cmd f5/00:00:00:00:00:a0 (SECURITY FREEZE LOCK) filtered out
May 23 22:12:12 maduranga-ThinkPad-T540p kernel: [44394.247417] ata1.00: supports DRM functions and may not be fully accessible
May 23 22:12:12 maduranga-ThinkPad-T540p kernel: [44394.248112] ata1.00: ACPI cmd ef/02:00:00:00:00:a0 (SET FEATURES) succeeded
May 23 22:12:12 maduranga-ThinkPad-T540p kernel: [44394.248115] ata1.00: ACPI cmd f5/00:00:00:00:00:a0 (SECURITY FREEZE LOCK) filtered out
May 23 22:12:12 maduranga-ThinkPad-T540p kernel: [44394.248284] ata1.00: supports DRM functions and may not be fully accessible
May 23 22:12:12 maduranga-ThinkPad-T540p kernel: [44394.248537] ata1.00: configured for UDMA/100
May 23 22:12:12 maduranga-ThinkPad-T540p kernel: [44394.250996] ata6.00: ACPI cmd e3/00:1f:00:00:00:a0 (IDLE) succeeded
May 23 22:12:12 maduranga-ThinkPad-T540p kernel: [44394.252530] ata6.00: ACPI cmd e3/00:02:00:00:00:a0 (IDLE) succeeded
May 23 22:12:12 maduranga-ThinkPad-T540p kernel: [44394.262170] ata6.00: ACPI cmd e3/00:1f:00:00:00:a0 (IDLE) succeeded
May 23 22:12:12 maduranga-ThinkPad-T540p kernel: [44394.262712] ata1: EH complete
May 23 22:12:12 maduranga-ThinkPad-T540p kernel: [44394.263819] ata6.00: ACPI cmd e3/00:02:00:00:00:a0 (IDLE) succeeded
May 23 22:12:12 maduranga-ThinkPad-T540p kernel: [44394.266965] ata6.00: configured for UDMA/133
May 23 22:12:12 maduranga-ThinkPad-T540p kernel: [44394.282767] ata6: EH complete

Кто-нибудь может подсказать мне, в чем может быть проблема? Аппаратная проблема или программная проблема?

Редактировать: вывод lspci -k | egrep 'VGA|3D' -A2 как предложено.

00:02.0 VGA compatible controller: Intel Corporation 4th Gen Core Processor Integrated Graphics Controller (rev 06)
    Subsystem: Lenovo Device 2210
    Kernel driver in use: i915