libdrm fails to get bus id

Submitted by Daniel Power

Assigned to Default DRI bug account

Link to original bug (#101837)

Description

radeontop is unable to display VRAM information because openDRM() returns -1

Graphics card: R9 270X
Distribution: Archlinux
Kernel Version: 4.11.9
libdrm version: 2.4.81 (also tested latest from git)
kernel driver: radeon

Output of radeontop with LIBGL_DEBUG=verbose enabled:

drmOpenDevice: node name is /dev/dri/card0
drmOpenDevice: open result is 4, (OK)
drmOpenByBusid: Searching for BusID pci:0000:01:00.0
drmOpenDevice: node name is /dev/dri/card0
drmOpenDevice: open result is 4, (OK)
drmOpenByBusid: drmOpenMinor returns 4
drmOpenByBusid: Interface 1.4 failed, trying 1.1
drmOpenByBusid: drmGetBusid reports 
drmOpenDevice: node name is /dev/dri/card1
drmOpenByBusid: drmOpenMinor returns -1
drmOpenDevice: node name is /dev/dri/card2
drmOpenByBusid: drmOpenMinor returns -1
drmOpenDevice: node name is /dev/dri/card3
drmOpenByBusid: drmOpenMinor returns -1
drmOpenDevice: node name is /dev/dri/card4
drmOpenByBusid: drmOpenMinor returns -1
drmOpenDevice: node name is /dev/dri/card5
drmOpenByBusid: drmOpenMinor returns -1
drmOpenDevice: node name is /dev/dri/card6
drmOpenByBusid: drmOpenMinor returns -1
drmOpenDevice: node name is /dev/dri/card7
drmOpenByBusid: drmOpenMinor returns -1
drmOpenDevice: node name is /dev/dri/card8
drmOpenByBusid: drmOpenMinor returns -1
drmOpenDevice: node name is /dev/dri/card9
drmOpenByBusid: drmOpenMinor returns -1
drmOpenDevice: node name is /dev/dri/card10
drmOpenByBusid: drmOpenMinor returns -1
drmOpenDevice: node name is /dev/dri/card11
drmOpenByBusid: drmOpenMinor returns -1
drmOpenDevice: node name is /dev/dri/card12
drmOpenByBusid: drmOpenMinor returns -1
drmOpenDevice: node name is /dev/dri/card13
drmOpenByBusid: drmOpenMinor returns -1
drmOpenDevice: node name is /dev/dri/card14
drmOpenByBusid: drmOpenMinor returns -1
drmOpenDevice: node name is /dev/dri/card15
drmOpenByBusid: drmOpenMinor returns -1
Failed to open DRM node, no VRAM support.
Collecting data, please wait....

Output of lspci -vnn:

01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Curacao XT / Trinidad XT [Radeon R7 370 / R9 270X/370X] (prog-if 00 [VGA controller])
	Subsystem: Hightech Information System Ltd. Device 2336
	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 49
	NUMA node: 0
	Region 0: Memory at c0000000 (64-bit, prefetchable) [size=256M]
	Region 2: Memory at fea00000 (64-bit, non-prefetchable) [size=256K]
	Region 4: I/O ports at e000 [size=256]
	Expansion ROM at 000c0000 [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) 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 8GT/s, Width x16, ASPM L0s L1, Exit Latency L0s <64ns, L1 <1us
			ClockPM- Surprise- LLActRep- BwNot- ASPMOptComp+
		LnkCtl:	ASPM Disabled; RCB 64 bytes Disabled- CommClk+
			ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
		LnkSta:	Speed 5GT/s, Width x16, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
		DevCap2: Completion Timeout: Not Supported, TimeoutDis-, LTR-, OBFF Not Supported
		AtomicOpsCap: 32bit- 64bit- 128bitCAS-
		DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis-, LTR-, OBFF Disabled
		AtomicOpsCtl: ReqEn-
		LnkCtl2: Target Link Speed: 8GT/s, EnterCompliance- SpeedDis-
			 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: 00000000fee00000  Data: 0000
	Capabilities: [100 v1] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
	Capabilities: [150 v2] 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-
	Capabilities: [200 v1] #15
	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
	Kernel modules: radeon, amdgpu

Original issue posted on radeontop github: https://github.com/clbr/radeontop/issues/48