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When rotating my display with xrandr --output DVI-0 --rotate left (or right or inverted), i get this weird, sort-of screen tearing effect that doesn't show up in screenshots.

(Image shows output of xrandr --output DVI-0 --rotate right with the monitor also rotated to the right) screen-tearing-like-effect

These lines are horizontal with respect to the actual monitor.

I am using Lubuntu 16.04. This used to work fine on Lubuntu 14.04.

My graphics card is a Radeon X600 according to lspci:

$ sudo lspci -vv
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV370 [Radeon X600/X600 SE] (prog-if 00 [VGA controller])
    Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] RV370 [Radeon X600/X600 SE]
    Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+
    Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
    Latency: 0, Cache Line Size: 64 bytes
    Interrupt: pin A routed to IRQ 27
    Region 0: Memory at d0000000 (64-bit, prefetchable) [size=128M]
    Region 2: Memory at dfde0000 (64-bit, non-prefetchable) [size=64K]
    Region 4: I/O ports at dc00 [size=256]
    Expansion ROM at dfe00000 [disabled] [size=128K]
    Capabilities: [50] Power Management version 2
            Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
            Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
    Capabilities: [58] Express (v1) Endpoint, MSI 00
            DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <128ns, L1 <2us
                    ExtTag+ AttnBtn- AttnInd- PwrInd- RBE- FLReset-
            DevCtl: Report errors: Correctable- Non-Fatal+ Fatal+ Unsupported-
                    RlxdOrd+ ExtTag+ PhantFunc- AuxPwr- NoSnoop+
                    MaxPayload 128 bytes, MaxReadReq 128 bytes
            DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr- TransPend-
            LnkCap: Port #0, Speed 2.5GT/s, Width x16, ASPM L0s L1, Exit Latency L0s <128ns, L1 <1us
                    ClockPM- Surprise- LLActRep- BwNot- ASPMOptComp-
            LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- CommClk+
                    ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
            LnkSta: Speed 2.5GT/s, Width x16, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
    Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit+
            Address: 00000000fee0100c  Data: 4172
    Capabilities: [100 v1] Advanced Error Reporting
            UESta:  DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol-
            UEMsk:  DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol-
            UESvrt: DLP+ SDES- TLP- FCP+ CmpltTO- CmpltAbrt- UnxCmplt- RxOF+ MalfTLP+ ECRC- UnsupReq- ACSViol-
            CESta:  RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr-
            CEMsk:  RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr-
            AERCap: First Error Pointer: 00, GenCap- CGenEn- ChkCap- ChkEn-
    Kernel driver in use: radeon
    Kernel modules: radeonfb, radeon

I have xserver-xorg-video-all installed (which depends on/also installed xserver-xorg-video-radeon, xserver-xorg-video-ati, and xserver-xorg-video-amdgpu).

This also happens with xrandr --output DVI-0 --reflect x (and y and xy).

Changing the resolution doesn't cause this to happen, but it will happen on any resolution if rotated or reflected. (... --rotate normal --reflect normal is the only orientation that works.)

Edit August 14, 2016: I have tested some more, and the 14.04 live iso works fine (with the radeon driver shown in lspci), but the 16.04 live iso has this problem along with my actual installation (also shows radeon driver).

Edit August 15, 2016: The Ubuntu 15.10 live iso also works correctly.

Edit November 19, 2017: The visual glitches do not affect the cursor.


Is there any way to fix this?

3

I am using Lubuntu 16.04 as well but this problem you are experiencing is related to the combination of using Ubuntu 16.04 (or higher) with ATI Radeon video cards (GPUs). Why?

Ubuntu uses totally different ATI Radeon drivers between version 14.04 and 16.04. Ubuntu 14.04 used AMD Radeon's proprietary drivers (called "fglrx"). Ubuntu 16.04 uses AMD Radeon OpenCL drivers (called "AMDGPU-PRO").

As a result of this huge switch over (done by AMD) to move away from their proprietary drives and instead use OpenCL drivers (which in the long-run is great of course and NVIDIA hasn't made the jump to OpenCL yet) they (AMD) are behind on coding full featured drivers for their products in OpenCL. Thus you can't rotate a display yet and other buggy problems. I don't think of rotating a display as an edge case but here is a guy complaining he can't get more than 8 GPUs to work!

I bought an AMD Radeon RX 480 video card that only has the new AMDGPU-PRO drivers for it!

  • I never installed flgrx manually on 14.04, just xserver-xorg-video-ati (and -radeon and -amd) Is/was the flgrx driver installed automatically? – pizzapants184 Aug 14 '16 at 1:55
  • fglrx is installed by default on 14.04. flgrx is not installed on 16.04. That last URL in my Answer tells you how to install and use fglrx in 16.04 – Rick Aug 14 '16 at 3:30
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    That link also says that Ubuntu uses the radeon driver by default – pizzapants184 Aug 14 '16 at 6:28
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    I have updated my question with more information, and realized I should report this as a bug, possibly against xserver-xorg-video-radeon? – pizzapants184 Aug 14 '16 at 6:32
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    Really? Wow, I thought one was still able to fallback to fglrx in 16.04 if they wanted to. I'll edit my Answer. – Rick Aug 14 '16 at 20:42

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