Re: [PATCH v2 RESEND] drivers/usb: Skip auto handoff for TI and RENESAS usb controllers

From: Babu Moger
Date: Mon Oct 24 2016 - 10:53:09 EST



On 10/24/2016 5:54 AM, Yoshihiro Shimoda wrote:
Hi,

From: Mathias Nyman
Sent: Monday, October 24, 2016 6:58 PM

On 22.10.2016 01:25, Babu Moger wrote:
Never seen XHCI auto handoff working on TI and RENESAS cards.
Eventually, we force handoff. This code forces the handoff
unconditionally. It saves 5 seconds boot time for each card.

Signed-off-by: Babu Moger <babu.moger@xxxxxxxxxx>
Do the Renesas and TI controllers still advertise the extended capability
for the handoff? (XHCI_EXT_CAPS_LEGACY)
I don't see this capability. Here is lspci output.

# lspci -s 0009:01:00.0 -vvv
0009:01:00.0 USB controller: Texas Instruments TUSB73x0 SuperSpeed USB 3.0 xHCI Host Controller (rev 02) (prog-if 30 [XHCI])
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 0000000e
Region 0: Memory at 100000000 (64-bit, non-prefetchable) [size=64K]
Region 2: Memory at 100010000 (64-bit, non-prefetchable) [size=8K]
Region 4: [virtual] Memory at fffdfdc000000000 (32-bit, non-prefetchable)
Region 5: [virtual] Memory at fffdfdc000000000 (32-bit, non-prefetchable)
[virtual] Expansion ROM at fffdfdc000000000 [disabled]
Capabilities: [40] 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: [48] MSI: Enable- Count=1/8 Maskable- 64bit+
Address: 0000000000000000 Data: 0000
Capabilities: [70] Express (v2) Endpoint, MSI 00
DevCap: MaxPayload 1024 bytes, PhantFunc 0, Latency L0s unlimited, L1 unlimited
ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset-
DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop-
MaxPayload 256 bytes, MaxReadReq 512 bytes
DevSta: CorrErr+ UncorrErr- FatalErr- UnsuppReq+ AuxPwr- TransPend-
LnkCap: Port #0, Speed 5GT/s, Width x1, ASPM L0s L1, Latency L0 <2us, L1 <64us
ClockPM+ Surprise- LLActRep- BwNot-
LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk-
ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
LnkSta: Speed 5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
DevCap2: Completion Timeout: Not Supported, TimeoutDis+, LTR-, OBFF Not Supported
DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis-, LTR-, OBFF Disabled
LnkCtl2: Target Link Speed: 5GT/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: [c0] MSI-X: Enable+ Count=8 Masked-
Vector table: BAR=2 offset=00000000
PBA: BAR=2 offset=00001000
Capabilities: [100 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: [150 v1] Device Serial Number 08-00-28-00-00-20-00-00
Kernel driver in use: xhci_hcd


Is this some known issue with these vendors controllers? Is there some documentation
about this, errata or anything?

Adding Yoshihiro Shimoda, he might know about the Renesas controller.
Thank you for adding me on this email.
However, unfortunately I don't know the detail about Renesas PCIe xHCI controllers.
(I know the xHCI controller of R-Car SoCs for now.)

Best regards,
Yoshihiro Shimoda