On 18.03.23 13:09, Michael Laß wrote:
Hi,
* Frame 41ff. (10.8s): Device connected on Port 2
* Around second 13: Running "screen /dev/ttyACM0 115200" on the host.
* Frame 131ff. (14.3s): The first "Hello World"
* Frame 174ff. (16.6s): Port suspend
Frame 174 is a control request (SET_FEATURE) to enable
remote wakeup
--> no more communication
* Around second 52 I did:
echo "on" > /sys/bus/usb/devices/5-2/power/control
* Frame 179ff. (52.8s): Port resume
* Frame 221ff. (53.3s): "Hello World"
* More "Hello World"s every three seconds as expected
So far
* Around second 73 I did:
echo "auto" > /sys/bus/usb/devices/5-2/power/control
* Frame 418ff. (73.7s): Port suspend
Frame 418 is the control request to enable remote wakeup
--> no more communication
Just to be clear, the device is generating data, isn't it?
So you would have expected data from a suspended device?
According to your earlier report, the device does support
remote wakeup:
Bus 006 Device 010: ID 04b4:0008 Cypress Semiconductor Corp. CDC ACM serial port
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 2 Communications
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 8
idVendor 0x04b4 Cypress Semiconductor Corp.
idProduct 0x0008 CDC ACM serial port
bcdDevice 0.00
iManufacturer 1 2012 Cypress Semiconductor
iProduct 2 Cypress-USB2UART-Ver1.0G
iSerial 4 827211C2091B
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 0x0043
bNumInterfaces 2
bConfigurationValue 1
iConfiguration 3 USB-UART Configuration
bmAttributes 0xa0
(Bus Powered)
Remote Wakeup
As far as I can tell, your device is simply broken and does not trigger
a remote wakeup when it should. It will need a kernel quirk.
Regards
Oliver
