Re: Cypress CDC ACM serial port not working correctly with autosuspend

[Oliver Neukum <oneukum@xxxxxxxx>]

On 29.01.23 12:44, Michael Laß wrote:

> 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

The device claims to support remote wakeup.

There are two possibilities here
1. The kernel fails to order remote wakeup to be enabled
2. The device's claim to support it is false.

What is to be done depends on which possibility is true.
Can you check an usbmon trace of the problem happening
for the control request enabling remote wakeup?

	Regards
		Oliver