Hi, when you are looking for Linux bugs, the Baytrail-based Lenovo Thinkpad Tablet 10 is the perfect choice. When you are looking for a tablet/laptop, not so much and I am regularly annoyed, among many other things, by GPU driver crashes that can be reproduced by switching from X to a text VT (using Ctrl-Alt-Fx). The trace in the kernel messages is below.
Kernel 3.13 does not have the problem. 4.0.0-rc4 does. Thanks for any help. Best regards, Sébastien [ 270.628890] ------------[ cut here ]------------ [ 270.628947] WARNING: CPU: 3 PID: 1254 at drivers/gpu/drm/i915/i915_gem.c:4285 i915_gem_object_unpin_fence+0x70/0x90 [i915]() [ 270.628950] WARN_ON(dev_priv->fence_regs[obj->fence_reg].pin_count <= 0) [ 270.628991] Modules linked in: hid_sensor_hub hid_multitouch wacom snd_soc_sst_baytrail_pcm snd_soc_sst_dsp snd_soc_sst_byt_rt5670_mach intel_powerclamp coretemp kvm_intel kvm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 lrw gf128mul dm_multipath glue_helper ablk_helper scsi_dh cryptd bnep brcmfmac rfcomm bluetooth brcmutil joydev cfg80211 snd_intel_sst_acpi snd_intel_sst_core snd_soc_sst_mfld_platform snd_soc_rt5670 dw_dmac dw_dmac_core snd_soc_rl6231 snd_soc_core snd_compress snd_seq_midi snd_pcm_dmaengine snd_seq_midi_event snd_pcm i2c_hid snd_rawmidi snd_seq snd_seq_device snd_timer snd acpi_pad binfmt_misc rfkill_gpio soundcore i2c_designware_platform i2c_designware_core spi_pxa2xx_platform snd_soc_sst_acpi lpc_ich 8250_dw mac_hid parport_pc ppdev lp parport nls_iso8859_1 dm_mirror dm_region_hash dm_log mmc_block hid_generic i915 i2c_algo_bit usbhid drm_kms_helper hid drm wmi video sdhci_acpi sdhci [ 270.629008] CPU: 3 PID: 1254 Comm: Xorg Not tainted 4.0.0-rc4 #6 [ 270.629009] Hardware name: LENOVO 20C3001VHH/20C3001VHH, BIOS GWET25WW (1.25) 10/17/2014 [ 270.629014] ffffffffa0227598 ffff8800b52fb798 ffffffff8178961f 0000000024662466 [ 270.629017] ffff8800b52fb7e8 ffff8800b52fb7d8 ffffffff8107254a ffff8800b52fb828 [ 270.629020] ffff8800357b3880 ffff880035520000 ffffffffa021bc80 ffff88003551c800 [ 270.629022] Call Trace: [ 270.629033] [<ffffffff8178961f>] dump_stack+0x45/0x57 [ 270.629040] [<ffffffff8107254a>] warn_slowpath_common+0x8a/0xc0 [ 270.629046] [<ffffffff810725c6>] warn_slowpath_fmt+0x46/0x50 [ 270.629076] [<ffffffffa018e380>] i915_gem_object_unpin_fence+0x70/0x90 [i915] [ 270.629112] [<ffffffffa01c9b55>] intel_unpin_fb_obj+0x25/0x50 [i915] [ 270.629146] [<ffffffffa01d599d>] intel_cleanup_plane_fb+0x3d/0x80 [i915] [ 270.629160] [<ffffffffa0118683>] drm_plane_helper_commit+0x1e3/0x2c0 [drm_kms_helper] [ 270.629173] [<ffffffffa01187fa>] drm_plane_helper_update+0x9a/0xf0 [drm_kms_helper] [ 270.629207] [<ffffffffa01d5339>] intel_crtc_set_config+0xc09/0xff0 [i915] [ 270.629234] [<ffffffffa005b93f>] drm_mode_set_config_internal+0x6f/0x110 [drm] [ 270.629246] [<ffffffffa0120b38>] restore_fbdev_mode+0xc8/0xf0 [drm_kms_helper] [ 270.629260] [<ffffffffa0122a59>] drm_fb_helper_restore_fbdev_mode_unlocked+0x29/0x80 [drm_kms_helper] [ 270.629272] [<ffffffffa0122ad2>] drm_fb_helper_set_par+0x22/0x50 [drm_kms_helper] [ 270.629306] [<ffffffffa01e424a>] intel_fbdev_set_par+0x1a/0x60 [i915] [ 270.629312] [<ffffffff81411d21>] fb_set_var+0x191/0x430 [ 270.629317] [<ffffffff8109c04d>] ? check_preempt_curr+0x8d/0xa0 [ 270.629321] [<ffffffff810a4088>] ? __enqueue_entity+0x78/0x80 [ 270.629325] [<ffffffff810ab421>] ? enqueue_entity+0x291/0xb90 [ 270.629330] [<ffffffff81408b41>] fbcon_blank+0x1d1/0x2d0 [ 270.629336] [<ffffffff814a0558>] do_unblank_screen+0xb8/0x1f0 [ 270.629341] [<ffffffff8149630e>] complete_change_console+0x5e/0xf0 [ 270.629344] [<ffffffff8149733c>] vt_ioctl+0xf9c/0x1180 [ 270.629362] [<ffffffffa0050979>] ? drm_ioctl+0x79/0x630 [drm] [ 270.629367] [<ffffffff81225c66>] ? fsnotify+0x306/0x490 [ 270.629372] [<ffffffff81489aac>] tty_ioctl+0x1fc/0xc90 [ 270.629377] [<ffffffff811fa268>] do_vfs_ioctl+0x2f8/0x510 [ 270.629382] [<ffffffff811e8ed5>] ? __sb_end_write+0x35/0x70 [ 270.629385] [<ffffffff811e6982>] ? vfs_write+0x172/0x1f0 [ 270.629389] [<ffffffff811fa501>] SyS_ioctl+0x81/0xa0 [ 270.629393] [<ffffffff817911cd>] system_call_fastpath+0x16/0x1b [ 270.629396] ---[ end trace 688362ce4f74239c ]--- [ 270.629428] ------------[ cut here ]------------ [ 270.629430] kernel BUG at drivers/gpu/drm/i915/i915_gem.c:4257! [ 270.629433] invalid opcode: 0000 [#1] SMP [ 270.629474] Modules linked in: hid_sensor_hub hid_multitouch wacom snd_soc_sst_baytrail_pcm snd_soc_sst_dsp snd_soc_sst_byt_rt5670_mach intel_powerclamp coretemp kvm_intel kvm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 lrw gf128mul dm_multipath glue_helper ablk_helper scsi_dh cryptd bnep brcmfmac rfcomm bluetooth brcmutil joydev cfg80211 snd_intel_sst_acpi snd_intel_sst_core snd_soc_sst_mfld_platform snd_soc_rt5670 dw_dmac dw_dmac_core snd_soc_rl6231 snd_soc_core snd_compress snd_seq_midi snd_pcm_dmaengine snd_seq_midi_event snd_pcm i2c_hid snd_rawmidi snd_seq snd_seq_device snd_timer snd acpi_pad binfmt_misc rfkill_gpio soundcore i2c_designware_platform i2c_designware_core spi_pxa2xx_platform snd_soc_sst_acpi lpc_ich 8250_dw mac_hid parport_pc ppdev lp parport nls_iso8859_1 dm_mirror dm_region_hash dm_log mmc_block hid_generic i915 i2c_algo_bit usbhid drm_kms_helper hid drm wmi video sdhci_acpi sdhci [ 270.629487] CPU: 3 PID: 1254 Comm: Xorg Tainted: G W 4.0.0-rc4 #6 [ 270.629488] Hardware name: LENOVO 20C3001VHH/20C3001VHH, BIOS GWET25WW (1.25) 10/17/2014 [ 270.629490] task: ffff8800b7024b30 ti: ffff8800b52f8000 task.ti: ffff8800b52f8000 [ 270.629518] RIP: 0010:[<ffffffffa018e1c2>] [<ffffffffa018e1c2>] i915_gem_object_ggtt_unpin+0xc2/0xd0 [i915] [ 270.629520] RSP: 0018:ffff8800b52fb840 EFLAGS: 00010246 [ 270.629521] RAX: ffff88003572fd00 RBX: ffff8800357b3880 RCX: 0000000000002504 [ 270.629523] RDX: ffff88003572fd00 RSI: ffff8800357b3940 RDI: ffff8800357b3880 [ 270.629525] RBP: ffff8800b52fb840 R08: ffff880035527e70 R09: 0000000000000000 [ 270.629526] R10: 00000000000312e8 R11: 0000000000000000 R12: ffff8800354ba060 [ 270.629527] R13: ffffffffa021bc80 R14: ffff88003551c800 R15: 0000000000000000 [ 270.629530] FS: 00007f6504cdd9c0(0000) GS:ffff88013fd80000(0000) knlGS:0000000000000000 [ 270.629532] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 270.629533] CR2: 0000000001fdbc00 CR3: 00000000b7ee3000 CR4: 00000000001007e0 [ 270.629534] Stack: [ 270.629538] ffff8800b52fb858 ffffffffa018e1e2 ffff8800357b3880 ffff8800b52fb878 [ 270.629541] ffffffffa01c9b5d ffff8800b52fb878 ffff8800357b3880 ffff8800b52fb898 [ 270.629544] ffffffffa01d599d 0000000000000000 ffff8800350a4000 ffff8800b52fb8f8 [ 270.629545] Call Trace: [ 270.629574] [<ffffffffa018e1e2>] i915_gem_object_unpin_from_display_plane+0x12/0x40 [i915] [ 270.629608] [<ffffffffa01c9b5d>] intel_unpin_fb_obj+0x2d/0x50 [i915] [ 270.629642] [<ffffffffa01d599d>] intel_cleanup_plane_fb+0x3d/0x80 [i915] [ 270.629654] [<ffffffffa0118683>] drm_plane_helper_commit+0x1e3/0x2c0 [drm_kms_helper] [ 270.629666] [<ffffffffa01187fa>] drm_plane_helper_update+0x9a/0xf0 [drm_kms_helper] [ 270.629700] [<ffffffffa01d5339>] intel_crtc_set_config+0xc09/0xff0 [i915] [ 270.629722] [<ffffffffa005b93f>] drm_mode_set_config_internal+0x6f/0x110 [drm] [ 270.629735] [<ffffffffa0120b38>] restore_fbdev_mode+0xc8/0xf0 [drm_kms_helper] [ 270.629748] [<ffffffffa0122a59>] drm_fb_helper_restore_fbdev_mode_unlocked+0x29/0x80 [drm_kms_helper] [ 270.629761] [<ffffffffa0122ad2>] drm_fb_helper_set_par+0x22/0x50 [drm_kms_helper] [ 270.629795] [<ffffffffa01e424a>] intel_fbdev_set_par+0x1a/0x60 [i915] [ 270.629799] [<ffffffff81411d21>] fb_set_var+0x191/0x430 [ 270.629803] [<ffffffff8109c04d>] ? check_preempt_curr+0x8d/0xa0 [ 270.629806] [<ffffffff810a4088>] ? __enqueue_entity+0x78/0x80 [ 270.629810] [<ffffffff810ab421>] ? enqueue_entity+0x291/0xb90 [ 270.629814] [<ffffffff81408b41>] fbcon_blank+0x1d1/0x2d0 [ 270.629818] [<ffffffff814a0558>] do_unblank_screen+0xb8/0x1f0 [ 270.629822] [<ffffffff8149630e>] complete_change_console+0x5e/0xf0 [ 270.629826] [<ffffffff8149733c>] vt_ioctl+0xf9c/0x1180 [ 270.629844] [<ffffffffa0050979>] ? drm_ioctl+0x79/0x630 [drm] [ 270.629848] [<ffffffff81225c66>] ? fsnotify+0x306/0x490 [ 270.629852] [<ffffffff81489aac>] tty_ioctl+0x1fc/0xc90 [ 270.629856] [<ffffffff811fa268>] do_vfs_ioctl+0x2f8/0x510 [ 270.629860] [<ffffffff811e8ed5>] ? __sb_end_write+0x35/0x70 [ 270.629863] [<ffffffff811e6982>] ? vfs_write+0x172/0x1f0 [ 270.629867] [<ffffffff811fa501>] SyS_ioctl+0x81/0xa0 [ 270.629870] [<ffffffff817911cd>] system_call_fastpath+0x16/0x1b [ 270.629904] Code: 20 20 74 dd 41 8d 41 0f 41 83 e1 f0 83 e0 0f 41 09 c1 84 c0 44 88 8a c0 00 00 00 75 07 80 a7 19 01 00 00 7f 5d c3 0f 1f 00 0f 0b <0f> 0b 0f 1f 40 00 0f 0b 66 0f 1f 44 00 00 0f 1f 44 00 00 55 48 [ 270.629931] RIP [<ffffffffa018e1c2>] i915_gem_object_ggtt_unpin+0xc2/0xd0 [i915] [ 270.629932] RSP <ffff8800b52fb840> [ 270.629936] ---[ end trace 688362ce4f74239d ]---
