[Bug 49789] New: External monitor flickers on xrandr or cat /sys/class/drm/card0-VGA-1/status

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=49789

             Bug #: 49789
           Summary: External monitor flickers on xrandr or cat
                    /sys/class/drm/card0-VGA-1/status
    Classification: Unclassified
           Product: DRI
           Version: XOrg CVS
          Platform: x86-64 (AMD64)
        OS/Version: All
            Status: NEW
          Severity: normal
          Priority: medium
         Component: DRM/Radeon
        AssignedTo: dri-devel at lists.freedesktop.org
        ReportedBy: h.judt at gmx.at


Created attachment 61441
  --> https://bugs.freedesktop.org/attachment.cgi?id=61441
Xorg.log

This issue is not reproducible with every external monitor, as far as I could
determine only projectors are concerned:

When I connect a monitor/projector to the VGA port of the Lenovo T400 and
perform "xrandr" or "cat /sys/class/drm/card0-VGA-1/status", the external
monitor flickers (parts of the screen black out horizontally). Since I use a
script which performs these commands periodically to detect whether the monitor
is still connected, this is obviously very annoying.

Changing the power profile doesn't have any effect.

lspci:
01:00.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI RV620
[Mobility Radeon HD 3400 Series] (prog-if 00 [VGA controller])
        Subsystem: Lenovo Device 210e
        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 45
        Region 0: Memory at d0000000 (32-bit, prefetchable) [size=256M]
        Region 1: I/O ports at 2000 [size=256]
        Region 2: Memory at cfff0000 (32-bit, non-prefetchable) [size=64K]
        [virtual] Expansion ROM at cff00000 [disabled] [size=128K]
        Capabilities: [50] Power Management version 3
                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 (v2) Legacy Endpoint, MSI 00
                DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <4us, L1
unlimited
                        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, Latency
L0 <64ns, L1 <1us
                        ClockPM- Surprise- LLActRep- BwNot-
                LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+
                        ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
                LnkSta: Speed 2.5GT/s, Width x16, TrErr- Train- SlotClk+
DLActive- BWMgmt- ABWMgmt-
                DevCap2: Completion Timeout: Not Supported, TimeoutDis-
                DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis-
                LnkCtl2: Target Link Speed: 2.5GT/s, EnterCompliance-
SpeedDis-, Selectable De-emphasis: -6dB
                         Transmit Margin: Normal Operating Range,
EnterModifiedCompliance- ComplianceSOS-
                         Compliance De-emphasis: -6dB
                LnkSta2: Current De-emphasis Level: -3.5dB,
EqualizationComplete-, EqualizationPhase1-
                         EqualizationPhase2-, EqualizationPhase3-,
LinkEqualizationRequest-
        Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit+
                Address: 00000000fee0100c  Data: 41a1
        Capabilities: [100 v1] Vendor Specific Information: ID=0001 Rev=1
Len=010 <?>
        Kernel driver in use: radeon

-- 
Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.