Created attachment 171801 [details] log of output from drm.debug Hi, I get these stack traces in dmesg. I've attached a text file with output from drm.debug=0xe if it is of some help. Mar 23 09:51:22 notebook kernel: ------------[ cut here ]------------ Mar 23 09:51:22 notebook kernel: WARNING: CPU: 0 PID: 0 at drivers/gpu/drm/i915/intel_uncore.c:551 hsw_unclaimed_reg_debug.isra.13+0x78/0x90 [i915]() Mar 23 09:51:22 notebook kernel: Unclaimed register detected before reading register 0x44200 Mar 23 09:51:22 notebook kernel: Modules linked in: xen_acpi_processor usbhid snd_hda_codec_realtek snd_hda_codec_hdmi snd_hda_codec_generic snd_hda_intel snd_hda_controller snd_hda_codec btusb i915 snd_hwdep snd_pcm snd_timer thinkpad_acpi ehci_pci snd ehci_hcd iwlmvm xhci_pci xhci_hcd drm_kms_helper drm iwlwifi usbcore iTCO_wdt lpc_ich i2c_i801 usb_common x86_pkg_temp_thermal coretemp Mar 23 09:51:22 notebook kernel: CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 4.0.0-rc4+ #4 Mar 23 09:51:22 notebook kernel: Hardware name: LENOVO 20BVCTO1WW/20BVCTO1WW, BIOS JBET45WW (1.10 ) 02/03/2015 Mar 23 09:51:22 notebook kernel: ffffffffa0370858 ffff88022ee03ca8 ffffffff817a9078 0000000000000000 Mar 23 09:51:22 notebook kernel: ffff88022ee03cf8 ffff88022ee03ce8 ffffffff81076a05 ffff8800a22d3f58 Mar 23 09:51:22 notebook kernel: ffff8800adc90060 ffff8800adc90000 ffff8800adc90068 ffff8800adc90060 Mar 23 09:51:22 notebook kernel: Call Trace: Mar 23 09:51:22 notebook kernel: <IRQ> [<ffffffff817a9078>] dump_stack+0x45/0x57 Mar 23 09:51:22 notebook kernel: [<ffffffff81076a05>] warn_slowpath_common+0x85/0xc0 Mar 23 09:51:22 notebook kernel: [<ffffffff81076a81>] warn_slowpath_fmt+0x41/0x50 Mar 23 09:51:22 notebook kernel: [<ffffffffa02fa2e8>] hsw_unclaimed_reg_debug.isra.13+0x78/0x90 [i915] Mar 23 09:51:22 notebook kernel: [<ffffffffa02fba27>] gen6_read32+0x57/0x1b0 [i915] Mar 23 09:51:22 notebook kernel: [<ffffffffa02e9dba>] gen8_irq_handler+0x4a/0x4a0 [i915] Mar 23 09:51:22 notebook kernel: [<ffffffff8100a31c>] ? xen_timer_interrupt+0x10c/0x150 Mar 23 09:51:22 notebook kernel: [<ffffffff810be357>] handle_irq_event_percpu+0x47/0x1a0 Mar 23 09:51:22 notebook kernel: [<ffffffff810be4e5>] handle_irq_event+0x35/0x60 Mar 23 09:51:22 notebook kernel: [<ffffffff810c10d7>] handle_edge_irq+0x77/0x110 Mar 23 09:51:22 notebook kernel: [<ffffffff810bd9e6>] generic_handle_irq+0x26/0x40 Mar 23 09:51:22 notebook kernel: [<ffffffff813abf12>] evtchn_fifo_handle_events+0x162/0x170 Mar 23 09:51:22 notebook kernel: [<ffffffff813a9127>] __xen_evtchn_do_upcall+0x47/0x80 Mar 23 09:51:22 notebook kernel: [<ffffffff813aad2f>] xen_evtchn_do_upcall+0x2f/0x50 Mar 23 09:51:22 notebook kernel: [<ffffffff817b32ce>] xen_do_hypervisor_callback+0x1e/0x40 Mar 23 09:51:22 notebook kernel: <EOI> [<ffffffff810013aa>] ? xen_hypercall_sched_op+0xa/0x20 Mar 23 09:51:22 notebook kernel: [<ffffffff810013aa>] ? xen_hypercall_sched_op+0xa/0x20 Mar 23 09:51:22 notebook kernel: [<ffffffff8100a020>] ? xen_safe_halt+0x10/0x20 Mar 23 09:51:22 notebook kernel: [<ffffffff8101d89e>] ? default_idle+0x1e/0xb0 Mar 23 09:51:22 notebook kernel: [<ffffffff8101e21a>] ? arch_cpu_idle+0xa/0x10 Mar 23 09:51:22 notebook kernel: [<ffffffff810ade04>] ? cpu_startup_entry+0x274/0x400 Mar 23 09:51:22 notebook kernel: [<ffffffff817a1a92>] ? rest_init+0x72/0x80 Mar 23 09:51:22 notebook kernel: [<ffffffff81ceb095>] ? start_kernel+0x43c/0x449 Mar 23 09:51:22 notebook kernel: [<ffffffff81ceaa49>] ? set_init_arg+0x55/0x55 Mar 23 09:51:22 notebook kernel: [<ffffffff81cea5ee>] ? x86_64_start_reservations+0x2a/0x2c Mar 23 09:51:22 notebook kernel: [<ffffffff81cee54b>] ? xen_start_kernel+0x542/0x54e Mar 23 09:51:22 notebook kernel: ---[ end trace c236e86d5a039bd6 ]--- Thanks, Adrian Owen
Created attachment 175601 [details] trace after starting mplayer I can reproduce this with current 4.1.0-rc1+ As soon as I start mplayer, this happens (but only once) This output is after a reboot via kexec.
Created attachment 175611 [details] trace after starting mplayer (coldreboot)
Created attachment 175621 [details] trace after starting mplayer (fully powered off #1)
Created attachment 175631 [details] trace after starting mplayer (fully powered off #2)
Created attachment 175641 [details] lshw Here my lshw output. Please tell me if you need more output or if you have a patch to test.
btw, it only happens with the xv video output driver of mplayer, not with x11 or gl
Furthermore, the stack trace only happens if xf86-intel driver has set Options "AccelMethod" "SNA". When I set AccelMethod UXA the error doesn't show in kernel messages. I'm currently running 4.0.0 but would be happy to try an alternate kernel version if this is helpful. I have both linux-stable git and Linus tree handy. I'm happy to try patches and run tests as needed. I tried the git intel driver and the "release stack" software versions described in 2015Q1 Intel Graphics Stack Release but I observed the same results. The hardware I have is 00:02.0 VGA compatible controller [0300]: Intel Corporation Broadwell-U Integrated Graphics [8086:1616] (rev 09) Adrian
Presumed fixed. If the problem persists with latest kernels, please file a bug at the freedesktop.org bugzilla [1], referencing this bug. Thank you. [1] https://bugs.freedesktop.org/enter_bug.cgi?product=DRI&component=DRM/Intel