High CPU load produced by USB (DW2)
Mirza Krak
mirza.krak at gmail.com
Wed Feb 14 00:57:08 PST 2018
On 8 February 2018 at 14:53, Minas Harutyunyan
<Minas.Harutyunyan at synopsys.com> wrote:
> On 2/8/2018 5:07 PM, Mirza Krak wrote:
>> On 8 February 2018 at 12:02, Minas Harutyunyan
>> <Minas.Harutyunyan at synopsys.com> wrote:
>>> Hi Mirza,
>>>
>>> On 2/7/2018 1:49 PM, Mirza Krak wrote:
>>
>> < snip >
>>
>>>
>>> Could you please provide additional info:
>>> 1. Does your core support descriptor DMA mode? (bits 31 and 30 of GHWCFG4).
>>> 2. Version of core (GSNPSID)?
>>
>> It does seem to support descriptor DMA mode, and content of both
>> GHWCFG4 and GSNPSID are posted below.
>>
>> root at esp5-d1:~# dmesg | grep -E "GHWCFG4|GSNPSID"
>> [ 1.109298] dwc2 ff540000.usb: GSNPSID @0xF0940040 : 0x4F54310A
>> [ 1.109344] dwc2 ff540000.usb: GHWCFG4 @0xF0940050 : 0xC8004030
>> [ 1.489016] dwc2 ff580000.usb: GSNPSID @0xF09C0040 : 0x4F54310A
>> [ 1.489063] dwc2 ff580000.usb: GHWCFG4 @0xF09C0050 : 0xDBF04030
>>
>> Full register dump at boot (no devices connected) can be found at [1].
>>
>>> 3. Do you connect any HS HUB between dwc core port and keyboard? Is it
>>> available connection scenarios when Split traffic generated?
>>
>> There is actually an HS HUB (FE1_QFP48) between dwc core and keyboard,
>> I was not aware of it but it is mounted on the board.
>>
>>
>> [1]. https://urldefense.proofpoint.com/v2/url?u=https-3A__gist.github.com_mirzak_a6245dddd4670f3b908a9783f9db8b0d&d=DwIFaQ&c=DPL6_X_6JkXFx7AXWqB0tg&r=6z9Al9FrHR_ZqbbtSAsD16pvOL2S3XHxQnSzq8kusyI&m=FuRmhDEOJlbUvuyApaxG_YmB514C3IOGSzs6Mq_fzC0&s=ELF0UP4IluOiL35JlnFjiltWZx-BcTIsTaPjaWb0RFk&e=
>>
> Actually your core supported DDMA mode, moreover core allow SW to
> dynamically switch between BDMA and DDMA after core reset.
> If dwc2 core work in DDMA mode then core can track (u)frames internally
> and unmasking SOF's not required, but Host in DDMA doesn't support Split
> transfers. This is why, in your case (FS/LS keyboard connected to HS
> HUB), core switched to BDMA and unmasking SOF interrupt to track (u)frames.
Thank you for your valuable respons.
It is indeed as you mentioned the combination of HS and FS/LS devices
that trigger the high CPU load. Running HS only devices does not
produce any noticeable load.
But I am confused by one thing, I have two different boards with the
same SoC and same version of the DWC2 IP. Both boards have an internal
USB hub for the external connectors, though it seems that they have
different types of HUB' s. And I only have problems with one of them.
The second board does not have a problem mixing HS and FS/LS devices.
Is it possible that the USB HUB has some kind of "offloading" for the
Split transfers?
Tinkerboard USB hub (works well when mixing HS and FS/LS devices)
----------------------------
$ lsusb -t
/: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=ehci-platform/1p, 480M
|__ Port 1: Dev 2, If 0, Class=Audio, Driver=, 480M
|__ Port 1: Dev 2, If 1, Class=Audio, Driver=, 480M
|__ Port 1: Dev 2, If 2, Class=Audio, Driver=, 480M
|__ Port 1: Dev 2, If 3, Class=Audio, Driver=, 480M
|__ Port 1: Dev 2, If 4, Class=Audio, Driver=, 480M
|__ Port 1: Dev 2, If 5, Class=Audio, Driver=, 480M
|__ Port 1: Dev 2, If 255, Class=Human Interface Device, Driver=usbhid, 480M
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=dwc2/1p, 480M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=dwc2/1p, 480M
|__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 3: Dev 4, If 0, Class=Audio, Driver=, 12M
|__ Port 3: Dev 4, If 1, Class=Audio, Driver=, 12M
|__ Port 4: Dev 3, If 0, Class=Human Interface Device,
Driver=usbhid, 12M
$ lsusb -d 05e3:0610 -v
Bus 001 Device 002: ID 05e3:0610 Genesys Logic, Inc. 4-port hub
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 9 Hub
bDeviceSubClass 0
bDeviceProtocol 2 TT per port
bMaxPacketSize0 64
idVendor 0x05e3 Genesys Logic, Inc.
idProduct 0x0610 4-port hub
bcdDevice 32.98
iManufacturer 0
iProduct 1 USB2.0 Hub
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 41
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xe0
Self Powered
Remote Wakeup
MaxPower 100mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 9 Hub
bInterfaceSubClass 0
bInterfaceProtocol 1 Single TT
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0001 1x 1 bytes
bInterval 12
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 1
bNumEndpoints 1
bInterfaceClass 9 Hub
bInterfaceSubClass 0
bInterfaceProtocol 2 TT per port
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0001 1x 1 bytes
bInterval 12
Hub Descriptor:
bLength 9
bDescriptorType 41
nNbrPorts 4
wHubCharacteristic 0x00e0
Ganged power switching
Ganged overcurrent protection
TT think time 32 FS bits
Port indicators
bPwrOn2PwrGood 50 * 2 milli seconds
bHubContrCurrent 100 milli Ampere
DeviceRemovable 0x00
PortPwrCtrlMask 0xff
Hub Port Status:
Port 1: 0000.0100 power
Port 2: 0000.0100 power
Port 3: 0000.0103 power enable connect
Port 4: 0000.0103 power enable connect
Device Qualifier (for other device speed):
bLength 10
bDescriptorType 6
bcdUSB 2.00
bDeviceClass 9 Hub
bDeviceSubClass 0
bDeviceProtocol 0 Full speed (or root) hub
bMaxPacketSize0 64
bNumConfigurations 1
can't get debug descriptor: Resource temporarily unavailable
Device Status: 0x0001
Self Powered
FireFly USB HUB (does not work well when mixing HS and FS/LS devices)
-----------------------
$ lsusb -t
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=dwc2/1p, 480M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=dwc2/1p, 480M
|__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 1: Dev 3, If 0, Class=Vendor Specific Class, Driver=, 480M
|__ Port 3: Dev 4, If 0, Class=Audio, Driver=snd-usb-audio, 12M
|__ Port 3: Dev 4, If 1, Class=Audio, Driver=snd-usb-audio, 12M
$ lsusb -d 1a40:0101 -v
Bus 001 Device 002: ID 1a40:0101 Terminus Technology Inc. Hub
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 9 Hub
bDeviceSubClass 0
bDeviceProtocol 2 TT per port
bMaxPacketSize0 64
idVendor 0x1a40 Terminus Technology Inc.
idProduct 0x0101 Hub
bcdDevice 1.00
iManufacturer 0
iProduct 1 USB 2.0 Hub [MTT]
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 41
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xe0
Self Powered
Remote Wakeup
MaxPower 100mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 9 Hub
bInterfaceSubClass 0
bInterfaceProtocol 1 Single TT
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0001 1x 1 bytes
bInterval 12
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 1
bNumEndpoints 1
bInterfaceClass 9 Hub
bInterfaceSubClass 0
bInterfaceProtocol 2 TT per port
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0001 1x 1 bytes
bInterval 12
Hub Descriptor:
bLength 9
bDescriptorType 41
nNbrPorts 4
wHubCharacteristic 0x0080
Ganged power switching
Ganged overcurrent protection
TT think time 8 FS bits
Port indicators
bPwrOn2PwrGood 50 * 2 milli seconds
bHubContrCurrent 100 milli Ampere
DeviceRemovable 0x00
PortPwrCtrlMask 0xff
Hub Port Status:
Port 1: 0000.0503 highspeed power enable connect
Port 2: 0000.0100 power
Port 3: 0000.0103 power enable connect
Port 4: 0000.0100 power
Device Qualifier (for other device speed):
bLength 10
bDescriptorType 6
bcdUSB 2.00
bDeviceClass 9 Hub
bDeviceSubClass 0
bDeviceProtocol 0 Full speed (or root) hub
bMaxPacketSize0 64
bNumConfigurations 1
can't get debug descriptor: Resource temporarily unavailable
Device Status: 0x0001
Self Powered
--
Med Vänliga Hälsningar / Best Regards
Mirza Krak
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