Created attachment 138491 [details] dmesg I checked out http://cgit.freedesktop.org/~agd5f/linux/log/?h=drm-next-3.16-wip (latest commit: 2472aac90b339e7abc186b615bcf533463b4c63a) and noticed that sometimes 2-3 cm wide horizontal lines would show up on the screen. They would only stay for a fraction of a second, before disappearing again. It's quite easy to trigger them by using the gnome expose function (the window overview). But they don't show up if I just let the computer idle at the desktop. I have a radeon 6950. I bisected the issue to this commit: fa7f517cb26eb1a1a1f0baffcced39f6c3ec3337 drm/radeon: rework page flip handling v4 I also noticed the following message (which is repeated multiple times): [ 8346.287462] WARNING: CPU: 1 PID: 342 at drivers/gpu/drm/drm_crtc.c:4315 drm_mode_page_flip_ioctl+0x2fd/0x320 [drm]() [ 8346.287464] Modules linked in: fuse snd_hda_codec_realtek snd_hda_codec_generic radeon i2c_algo_bit drm_kms_helper ttm iTCO_wdt iTCO_vendor_support snd_hda_codec_hdmi drm eeepc_wmi nls_cp437 asus_wmi sparse_keymap mxm_wmi vfat fat x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel evdev kvm crct10dif_pclmul crct10dif_common crc32_pclmul ecb btusb ghash_clmulni_intel bluetooth aesni_intel crc16 aes_x86_64 glue_helper lrw rfkill gf128mul ablk_helper cryptd microcode psmouse serio_raw pcspkr i2c_i801 lpc_ich i2c_core mfd_core fan snd_hda_intel snd_hda_controller snd_hda_codec snd_hwdep snd_pcm snd_timer video thermal snd e1000e mei_me ptp mei pps_core shpchp wmi soundcore processor button btrfs xor raid6_pq sr_mod cdrom sd_mod hid_generic usbhid hid ehci_pci ahci libahci xhci_hcd ehci_hcd libata [ 8346.287529] firewire_ohci crc32c_intel firewire_core crc_itu_t scsi_mod usbcore usb_common [ 8346.287538] CPU: 1 PID: 342 Comm: Xorg Tainted: G W 3.15.0-rc8-ARCH+ #12 [ 8346.287540] Hardware name: System manufacturer System Product Name/P8P67 PRO, BIOS 3602 11/01/2012 [ 8346.287542] 0000000000000009 ffff88020e96fd08 ffffffff814ecc2a 0000000000000000 [ 8346.287546] ffff88020e96fd40 ffffffff81065e0d ffff88020e96fdf8 ffff880211958068 [ 8346.287550] ffff88020a67cd80 ffff880211958018 0000000000000000 ffff88020e96fd50 [ 8346.287554] Call Trace: [ 8346.287561] [<ffffffff814ecc2a>] dump_stack+0x4d/0x6f [ 8346.287566] [<ffffffff81065e0d>] warn_slowpath_common+0x7d/0xa0 [ 8346.287569] [<ffffffff81065eea>] warn_slowpath_null+0x1a/0x20 [ 8346.287577] [<ffffffffa0f1fffd>] drm_mode_page_flip_ioctl+0x2fd/0x320 [drm] [ 8346.287583] [<ffffffffa0f0ea7b>] drm_ioctl+0x1db/0x5f0 [drm] [ 8346.287591] [<ffffffffa0f1fd00>] ? drm_mode_gamma_get_ioctl+0xf0/0xf0 [drm] [ 8346.287602] [<ffffffffa0fb104c>] radeon_drm_ioctl+0x4c/0x80 [radeon] [ 8346.287607] [<ffffffff811c6b48>] do_vfs_ioctl+0x2c8/0x4b0 [ 8346.287612] [<ffffffff811d0dde>] ? __fget+0x6e/0xb0 [ 8346.287615] [<ffffffff811c6db1>] SyS_ioctl+0x81/0xa0 [ 8346.287619] [<ffffffff814fb16d>] system_call_fastpath+0x1a/0x1f [ 8346.287622] ---[ end trace 7f747cd881a3fb9e ]---
Created attachment 138561 [details] Move fb update from radeon_flip_work_func() to radeon_crtc_page_flip() This (untested) patch should fix at least the warnings in dmesg, not sure about the visual artifacts though.
(In reply to Michel Dänzer from comment #1) > Created attachment 138561 [details] > Move fb update from radeon_flip_work_func() to radeon_crtc_page_flip() > > This (untested) patch should fix at least the warnings in dmesg, not sure > about the visual artifacts though. Yep, the warnings are now gone, but the artifacts are still there
Tested the latest 3.16-rc4 and the artifacts are now gone.