Hi, On Thu, Jan 22, 2015 at 08:37:45AM +0100, Yegor Yefremov wrote: > I have the same experience with 3.15. The switching is working when > CONFIG_USB_MUSB_DUAL_ROLE is set and dr_mode = "otg". But since 3.16 > it seems to be broken. Still had no time to bisect this. I've been giving a few versions (from v3.15 to Tuesday's linux-next) a try, and I always see the same behaviour now: - Booting as a gadget (ie, with a USB cable plugged in), and swapping the cable for a (real, this time) USB OTG cable with a USB key never works. When the device is plugged, all I get is [ 262.944846] usb 1-1: new high-speed USB device number 2 using musb-hdrc [ 278.064748] usb 1-1: device descriptor read/64, error -110 Putting in back in gadget results with a load of continuous: [ 315.258839] musb_bus_suspend 2484: trying to suspend as a_wait_vfall while active - Booting as a host, or with nothing connected to it actually work, up to a few plug-a-device-then-plug-a-host cycles, where you end up with the following logs when disconnecting the device (somehow, it always happens when it is set in host mode). [ 12.969075] CAUTION: musb: Babble Interrupt Occurred [ 12.974445] CAUTION: musb: Babble Interrupt Occurred [ 12.979637] musb_stage0_irq 789: unhandled DISCONNECT transition (a_wait_bcon) [ 12.988498] usb 1-1: USB disconnect, device number 2 [ 13.071849] musb-hdrc musb-hdrc.0.auto: Restarting MUSB to recover from Babble Plugging back our USB cable, with the AM335x acting as a device work once. Then, when it switches to the host mode, we end up with the same scenario than in the coldplug as gadget case: USB read error, before then having all the a_wait_vfall messages. Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com
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