[questions] why doesn't BCM5788 driver use MSI? What should I do to enable it?

[questions] why doesn't BCM5788 driver use MSI? What should I do to enable it?

[Jike Song]

Hi,

Is there any method to get BCM5788 (tg3 driver) work with MSI enabled?
lspci tells me MSI is supported by BCM5788 card:

$ sudo lspci -vvv -d 0x14e4:0x169c
02:01.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5788
Gigabit Ethernet (rev 03)
	Subsystem: Hewlett-Packard Company Device 30b0
	Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr-
Stepping- SERR- FastB2B- DisINTx-
	Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort-
<TAbort- <MAbort- >SERR- <PERR- INTx-
	Latency: 64 (16000ns min), Cache Line Size: 64 bytes
	Interrupt: pin A routed to IRQ 23
	Region 0: Memory at d4000000 (32-bit, non-prefetchable) [size=64K]
	Expansion ROM at <ignored> [disabled]
	Capabilities: [48] Power Management version 2
		Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot+,D3cold+)
		Status: D0 PME-Enable- DSel=0 DScale=1 PME-
	Capabilities: [50] Vital Product Data
pcilib: sysfs_read_vpd: read failed: Connection timed out
		Not readable
	Capabilities: [58] MSI: Mask- 64bit+ Count=1/8 Enable-
		Address: bfdfb567bfff7ff8  Data: ffff
	Kernel driver in use: tg3
	Kernel modules: tg3

-- 
Thanks,
Jike

Re: [questions] why doesn't BCM5788 driver use MSI? What should I do to enable it?

[Michael Chan]

Jike Song wrote:

> Is there any method to get BCM5788 (tg3 driver) work with MSI enabled?
> lspci tells me MSI is supported by BCM5788 card:
>

The capability is there, but the hardware implementation is buggy.
The interrupt cannot be properly disabled, among other issues.  MSI
was fixed in later versions of the PCIE chips.