Arch Linux

Description: The problem with starting the server with the Radeon HD 6400M Series and KMS. At least when I use vga_switcheroo.

Xorg.0.log:
[ 125.929] Backtrace:
[ 125.945] 0: /usr/bin/X (xorg_backtrace+0x49) [0x81b7609]
[ 125.945] 1: /usr/bin/X (0x8048000+0x173266) [0x81bb266]
[ 125.945] 2: (vdso) (__kernel_rt_sigreturn+0x0) [0xb776540c]
[ 125.945] 3: /usr/bin/X (xf86SetScrnInfoModes+0x30c) [0x80e99bc]
[ 125.945] 4: /usr/bin/X (xf86InitialConfiguration+0x156b) [0x80ed58b]
[ 125.945] 5: /usr/lib/xorg/modules/drivers/radeon_drv.so (0xb70ed000+0xd0feb) [0xb71bdfeb]
[ 125.945] 6: /usr/lib/xorg/modules/drivers/radeon_drv.so (0xb70ed000+0xcc355) [0xb71b9355]
[ 125.945] 7: /usr/bin/X (InitOutput+0x951) [0x80b9dc1]
[ 125.945] 8: /usr/bin/X (0x8048000+0x1cb96) [0x8064b96]
[ 125.945] 9: /lib/libc.so.6 (__libc_start_main+0xf5) [0xb73ea3d5]
[ 125.945] 10: /usr/bin/X (0x8048000+0x1d0a9) [0x80650a9]
[ 125.945]
[ 125.945] Segmentation fault at address (nil)
[ 125.945]
Fatal server error:
[ 125.945] Caught signal 11 (Segmentation fault). Server aborting

lspci -vv:
01:00.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI Seymour [Radeon HD 6400M Series] (prog-if 00 [VGA controller])
Subsystem: Hewlett-Packard Company Device 167d
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 47
Region 0: Memory at b0000000 (64-bit, prefetchable) [size=256M]
Region 2: Memory at d4a00000 (64-bit, non-prefetchable) [size=128K]
Region 4: I/O ports at 5000 [size=256]
Expansion ROM at d4a20000 [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 256 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 512 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: -6dB, EqualizationComplete-, EqualizationPhase1-
EqualizationPhase2-, EqualizationPhase3-, LinkEqualizationRequest-
Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit+
Address: 00000000fee0f00c Data: 4199
Capabilities: [100 v1] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
Capabilities: [150 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

/boot/grub/menu.lst:
kernel /boot/vmlinuz-linux root=/dev/sda1 ro radeon.modeset=1

I have tried several drivers. The problem is not reproduced in 6.12, but 6.12 does not work with my card.