[drm:radeon_dp_link_train] *ERROR* clock recovery failed -bisected

[Deucher, Alexander]

> -----Original Message-----
> From: Ken Moffat [mailto:zarniwhoop at ntlworld.com]
> Sent: Thursday, March 03, 2016 6:47 PM
> To: Deucher, Alexander; StDenis, Tom
> Cc: dri-devel at lists.freedesktop.org; linux-kernel at vger.kernel.org
> Subject: [drm:radeon_dp_link_train] *ERROR* clock recovery failed -
> bisected
> 
> On Thu, Mar 03, 2016 at 02:38:11AM +0000, Ken Moffat wrote:
> > One of my machines is an A10 Kaveri desktop, with a good old VGA
> > connection to the monitor.  I've only just started trying to boot
> > any 4.5 kernel on it, but with 4.5.0-rc6 and now linus's tree from a
> > few hours ago (4.5.0-rc6-00018-gf983cd3) I get a blank screen, with
> > no video signal, as soon as it tries to switch to a framebuffer.
> >
> > Comparing the logs, the first bad attempt had a couple of new error
> > messages, everything else in the logs looked normal -
> >
> > Mar  1 19:31:10 deluxe kernel: [    2.543163] fbcon: radeondrmfb (fb0) is
> primary device
> > Mar  1 19:31:10 deluxe kernel: [    2.654179] [drm:radeon_dp_link_train]
> *ERROR* clock recovery reached max voltage
> > Mar  1 19:31:10 deluxe kernel: [    2.654181] [drm:radeon_dp_link_train]
> *ERROR* clock recovery failed
> > Mar  1 19:31:10 deluxe kernel: [    2.677142] Console: switching to colour
> frame buffer device 200x56
> > Mar  1 19:31:10 deluxe kernel: [    2.680435] radeon 0000:00:01.0: fb0:
> radeondrmfb frame buffer device
> >
> Bisection pointed to
> 
> 092c96a8ab9d1bd60ada2ed385cc364ce084180e is the first bad commit
> commit 092c96a8ab9d1bd60ada2ed385cc364ce084180e
> Author: Alex Deucher <alexander.deucher at amd.com>
> Date:   Thu Dec 17 10:23:34 2015 -0500
> 
>     drm/radeon: fix dp link rate selection (v2)
> 
>     Need to properly handle the max link rate in the dpcd.
>     This prevents some cases where 5.4 Ghz is selected when
>     it shouldn't be.
> 
>     v2: simplify logic, add array bounds check
> 
>     Reviewed-by: Tom St Denis <tom.stdenis at amd.com>
>     Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
> 
> I have now reverted that commit from that version of linus's tree and
> the machine everything is back to normal.
> 

The attached radeon patch should fix it.  I accidently dropped the special handling for NUTMEG DP to VGA bridge chips.

> This mobo does not have a DP connector.
> 

The VGA port uses a DP to VGA bridge chip.

Alex

> lspci reports the graphics part is
> 
> 00:01.0 VGA compatible controller: Advanced Micro Devices, Inc.
> [AMD/ATI] Kaveri [Radeon R7 Graphics] (prog-if 00 [VGA controller])
>         Subsystem: Gigabyte Technology Co., Ltd Kaveri [Radeon R7 Graphics]
>         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- <PER
> R- INTx-
>         Latency: 0, Cache Line Size: 64 bytes
>         Interrupt: pin A routed to IRQ 26
>         Region 0: Memory at c0000000 (64-bit, prefetchable) [size=256M]
>         Region 2: Memory at d0000000 (64-bit, prefetchable) [size=8M]
>         Region 4: I/O ports at f000 [size=256]
>         Region 5: Memory at feb00000 (32-bit, non-prefetchable) [size=256K]
>         Expansion ROM at feb40000 [disabled] [size=128K]
>         Capabilities: [48] Vendor Specific Information: Len=08 <?>
>         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) Root Complex Integrated Endpoint, MSI 00
>                 DevCap: MaxPayload 256 bytes, PhantFunc 0
>                         ExtTag+ RBE+
>                 DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
>                         RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+
>                         MaxPayload 128 bytes, MaxReadReq 512 bytes
>                 DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr-
> TransPend-
>                 DevCap2: Completion Timeout: Not Supported, TimeoutDis-, LTR-,
> OBFF Not Supported
>                 DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis-, LTR-, OBFF
> Disabled
>         Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit+
>                 Address: 00000000fee0f00c  Data: 4172
>         Capabilities: [100 v1] Vendor Specific Information: ID=0001 Rev=1
> Len=010 <?>
>         Capabilities: [270 v1] #19
>         Capabilities: [2b0 v1] Address Translation Service (ATS)
>                 ATSCap: Invalidate Queue Depth: 00
>                 ATSCtl: Enable-, Smallest Translation Unit: 00
>         Capabilities: [2c0 v1] Page Request Interface (PRI)
>                 PRICtl: Enable- Reset-
>                 PRISta: RF- UPRGI- Stopped+
>                 Page Request Capacity: 00000020, Page Request Allocation: 00000000
>         Capabilities: [2d0 v1] Process Address Space ID (PASID)
>                 PASIDCap: Exec- Priv-, Max PASID Width: 10
>                 PASIDCtl: Enable- Exec- Priv-
>         Kernel driver in use: radeon
> 
> I've attached my config.  Please let me know if there is anything I
> can do to help fix this.
> 
> ĸen
> --
> This email was written using 100% recycled letters.
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