• Mauro Carvalho Chehab's avatar
    dt-bindings: document a new quirk for dwc3 · 31b5de5f
    Mauro Carvalho Chehab authored
    At Hikey 970, setting the SPLIT disable at the General
    User Register 3 is required.
    
    Without that, the URBs generated by the usbhid driver
    return -EPROTO errors. That causes the code at
    hid-core.c to call hid_io_error(), which schedules
    a reset_work, causing a call to hid_reset().
    
    In turn, the code there will call:
    
    	usb_queue_reset_device(usbhid->intf);
    
    The net result is that the input devices won't work, and
    will be reset on every 0.5 seconds:
    
    	[   33.122384] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002
    	[   33.378220] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd
    	[   33.698394] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0000
    	[   34.882365] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002
    	[   35.138217] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd
    	[   35.458617] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0000
    	[   36.642392] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002
    	[   36.898207] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd
    	[   37.218598] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0000
    	[   38.402368] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002
    	[   38.658174] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd
    	[   38.978594] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0000
    	[   40.162361] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002
    	[   40.418148] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd
    	...
    	[  397.698132] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd
    Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
    Signed-off-by: default avatarFelipe Balbi <balbi@kernel.org>
    31b5de5f
dwc3.txt 6.11 KB