USB experts help needed

[Hans Petter Selasky]

On 2020-08-26 10:16, Wojciech Puchar wrote:
> i am implementing my own "mass storage device" (actually fake but 
> doesn't matter) on microcontroller.
> 
> I already finished implementing control endpoint part so it is properly 
> detected configured itp.
> 
> But i have no idea why i'm getting USB reset after successful reply to 
> "get max lun" control endpoint command  (0xFE). i reply with one byte of 
> zero according to USB mass storage specs.
> 
> below is log from my microcontroller's program
> 
> USB: RESET
> USB: Setting USB address 6
> USB: Host received response from control interface.
> USB: Sending config descriptor 0100:8 bytes.
> USB: Host received response from control interface.
> USB: Sending config descriptor 0100:18 bytes.
> USB: Host received response from control interface.
> USB: Sending config descriptor 0300:2 bytes.
> USB: Host received response from control interface.
> USB: Sending config descriptor 0300:4 bytes.
> USB: Host received response from control interface.
> USB: Sending config descriptor 0301:2 bytes.
> USB: Host received response from control interface.
> USB: Sending config descriptor 0301:32 bytes.
> USB: Host received response from control interface.
> USB: Sending config descriptor 0302:2 bytes.
> USB: Host received response from control interface.
> USB: Sending config descriptor 0302:12 bytes.
> USB: Host received response from control interface.
> USB: Sending config descriptor 0200:9 bytes.
> USB: Host received response from control interface.
> USB: Sending config descriptor 0200:32 bytes.
> USB: Host received response from control interface.
> USB: Set configuration 1 received.
> USB: Host received response from control interface.
> USB: Mass storage get MAX LUN received.
> USB: Host received response from control interface.
> USB: RESET
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> USB: Setting USB address 6
> USB: Host received response from control interface.
> USB: Sending config descriptor 0100:8 bytes.
> USB: Host received response from control interface.
> USB: Sending config descriptor 0100:18 bytes.
> USB: Host received response from control interface.
> USB: Sending config descriptor 0200:9 bytes.
> USB: Host received response from control interface.
> USB: Sending config descriptor 0200:32 bytes.
> USB: Host received response from control interface.
> USB: Set configuration 1 received.
> USB: Host received response from control interface.
> USB: Mass storage reset received.
> USB: Host received response from control interface.
> USB: Clear endpoint 1 received.
> USB: Host received response from control interface.
> 

Are you sure the firmware on your device didn't crash and reboot?

--HPS