Commit 9df89d85b407690afa46ddfbccc80bec6869971d "usbcore: set lpm_capable field for LPM capable root hubs" was created under the assumption that all USB host controllers should have USB 3.0 Link PM enabled for all devices under the hosts.
Unfortunately, that's not the case. The xHCI driver relies on knowledge of the host hardware scheduler to calculate the LPM U1/U2 timeout values, and it only sets lpm_capable to one for Intel host controllers (that have the XHCI_LPM_SUPPORT quirk set). When LPM is enabled for some Fresco Logic hosts, it causes failures with a AgeStar 3UBT USB 3.0 hard drive dock: Jan 11 13:59:03 sg-laptop kernel: usb 3-1: new SuperSpeed USB device number 2 using xhci_hcd Jan 11 13:59:03 sg-laptop kernel: usb 3-1: Set SEL for device-initiated U1 failed. Jan 11 13:59:08 sg-laptop kernel: usb 3-1: Set SEL for device-initiated U2 failed. Jan 11 13:59:08 sg-laptop kernel: usb-storage 3-1:1.0: USB Mass Storage device detected Jan 11 13:59:08 sg-laptop mtp-probe[613]: checking bus 3, device 2: "/sys/devices/pci0000:00/0000:00:1c.3/0000:04:00.0/usb3/3-1" Jan 11 13:59:08 sg-laptop mtp-probe[613]: bus: 3, device: 2 was not an MTP device Jan 11 13:59:08 sg-laptop kernel: scsi6 : usb-storage 3-1:1.0 Jan 11 13:59:13 sg-laptop kernel: usb 3-1: Set SEL for device-initiated U1 failed. Jan 11 13:59:18 sg-laptop kernel: usb 3-1: Set SEL for device-initiated U2 failed. Jan 11 13:59:18 sg-laptop kernel: usbcore: registered new interface driver usb-storage Jan 11 13:59:40 sg-laptop kernel: usb 3-1: reset SuperSpeed USB device number 2 using xhci_hcd Jan 11 13:59:41 sg-laptop kernel: usb 3-1: device descriptor read/8, error -71 Jan 11 13:59:41 sg-laptop kernel: usb 3-1: reset SuperSpeed USB device number 2 using xhci_hcd Jan 11 13:59:46 sg-laptop kernel: usb 3-1: device descriptor read/8, error -110 Jan 11 13:59:46 sg-laptop kernel: scsi 6:0:0:0: Device offlined - not ready after error recovery Jan 11 13:59:46 sg-laptop kernel: usb 3-1: USB disconnect, device number 2 lspci for the affected host: 04:00.0 0c03: 1b73:1000 (rev 04) (prog-if 30 [XHCI]) Subsystem: 1043:1039 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 19 Region 0: Memory at dd200000 (32-bit, non-prefetchable) [size=64K] 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: [68] MSI: Enable- Count=1/1 Maskable- 64bit+ Address: 0000000000000000 Data: 0000 Capabilities: [80] Express (v1) Endpoint, MSI 00 DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <2us, L1 <32us 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 x1, ASPM L0s L1, Latency L0 unlimited, L1 unlimited ClockPM- Surprise- LLActRep- BwNot- LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+ ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt- LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt- Kernel driver in use: xhci_hcd Kernel modules: xhci_hcd The commit was backported to stable kernels, and will need to be reverted there as well. Signed-off-by: Sarah Sharp <sarah.a.sh...@intel.com> Reported-by: Sergey Galanov <sergey.e.gala...@gmail.com> Cc: sta...@vger.kernel.org --- drivers/usb/core/hcd.c | 1 - drivers/usb/core/hub.c | 7 +------ drivers/usb/core/usb.h | 1 - 3 files changed, 1 insertion(+), 8 deletions(-) diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 199aaea6bfe0..2518c3250750 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -1032,7 +1032,6 @@ static int register_root_hub(struct usb_hcd *hcd) dev_name(&usb_dev->dev), retval); return retval; } - usb_dev->lpm_capable = usb_device_supports_lpm(usb_dev); } retval = usb_new_device (usb_dev); diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index babba885978d..64ea21971be2 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -128,7 +128,7 @@ struct usb_hub *usb_hub_to_struct_hub(struct usb_device *hdev) return usb_get_intfdata(hdev->actconfig->interface[0]); } -int usb_device_supports_lpm(struct usb_device *udev) +static int usb_device_supports_lpm(struct usb_device *udev) { /* USB 2.1 (and greater) devices indicate LPM support through * their USB 2.0 Extended Capabilities BOS descriptor. @@ -149,11 +149,6 @@ int usb_device_supports_lpm(struct usb_device *udev) "Power management will be impacted.\n"); return 0; } - - /* udev is root hub */ - if (!udev->parent) - return 1; - if (udev->parent->lpm_capable) return 1; diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h index c49383669cd8..823857767a16 100644 --- a/drivers/usb/core/usb.h +++ b/drivers/usb/core/usb.h @@ -35,7 +35,6 @@ extern int usb_get_device_descriptor(struct usb_device *dev, unsigned int size); extern int usb_get_bos_descriptor(struct usb_device *dev); extern void usb_release_bos_descriptor(struct usb_device *dev); -extern int usb_device_supports_lpm(struct usb_device *udev); extern char *usb_cache_string(struct usb_device *udev, int index); extern int usb_set_configuration(struct usb_device *dev, int configuration); extern int usb_choose_configuration(struct usb_device *udev); -- 1.8.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html