Am Mittwoch, 2. September 2020, 10:28:21 CEST schrieb Ludwig Nussel:
Guillaume Gardet wrote:
-----Original Message----- From: Ludwig Nussel <ludwig.nussel@suse.de> Sent: 01 September 2020 18:51 To: opensuse-arm@opensuse.org Subject: [opensuse-arm] rpi to rpi via usb gadget
Hi,
I've tried to use the USB OTG features of the RPi4 to remote control an RPi3 with MicroOS 15.2 using pikvm. That works fine as soon as Linux is booted in the RPi3. Fails in U-Boot and therefore grub though. U-Boot doesn't detect the simulated devices. On the Pi4 the kernel throws error messages: [ 104.168251] configfs-gadget gadget: usb_ep_queue error on int endpoint -11
Is that an issue on our side in U-Boot or somewhere else?
Could it be related to https://github.com/raspberrypi/firmware/issues/1322 ?
The pikvm website also mentions that the OTG mode doesn't work with some PC BIOSes¹ while an Arduino does the job. So maybe that OTG descriptor confuses them too? Is there a way to make the kernel not generate that descriptor to test?
Forcing the controller in peripheral only mode might work. Something
Fabian Vogt wrote: like that
as device tree overlay maybe:
&usb { dr_mode = "peripheral"; };
Fabian also found that it's as simple as dtoverlay=dwc2,dr_mode=peripheral to get rid of the otg descriptor. That's not the issue though. I found that when setting the hid subclass to 0 the device appears in u-boot. Still doesn't work though. It's not specific to the rpi3 either. Connecting a A10 olinuxino on the other side also gets no keyboard input either. Looking at "usb info" one can see that the gadget has two endpoints. One for input and one for output. Whereas real keyboards and also an Arduino pretending to be a keyboard only has an input endpoint. Could that be relevant? I couldn't find how to disable the second endpoint via configfs though. Any ideas? cu Ludwig -- (o_ Ludwig Nussel //\ V_/_ http://www.suse.com/ SUSE Software Solutions Germany GmbH, GF: Felix Imendörffer HRB 36809 (AG Nürnberg) -- To unsubscribe, e-mail: opensuse-arm+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-arm+owner@opensuse.org