We've found that while in host mode, using Android, if one runs the command: stop adbd The existing usb devices being utilized in host mode are disconnected. This is most visible with usb networking devices. This seems to be due to adbd closing the file: /dev/usb-ffs/adb/ep0 Which calls ffs_ep0_release() and the following backtrace: [<ffffff800875a430>] dwc2_hsotg_ep_disable+0x148/0x150 [<ffffff800875a498>] dwc2_hsotg_udc_stop+0x60/0x110 [<ffffff8008787950>] usb_gadget_remove_driver+0x58/0x78 [<ffffff80087879e4>] usb_gadget_unregister_driver+0x74/0xe8 [<ffffff80087850c0>] unregister_gadget+0x28/0x58 [<ffffff800878511c>] unregister_gadget_item+0x2c/0x40 [<ffffff8008790ea8>] ffs_data_clear+0xe8/0xf8 [<ffffff8008790ed8>] ffs_data_reset+0x20/0x58 [<ffffff8008793218>] ffs_data_closed+0x98/0xe8 [<ffffff80087932d8>] ffs_ep0_release+0x20/0x30 Then when dwc2_hsotg_ep_disable() is called, we call kill_all_requests() which causes a bunch of the following messages: dwc2 f72c0000.usb: Mode Mismatch Interrupt: currently in Host mode dwc2 f72c0000.usb: Mode Mismatch Interrupt: currently in Host mode dwc2 f72c0000.usb: Mode Mismatch Interrupt: currently in Host mode dwc2 f72c0000.usb: Mode Mismatch Interrupt: currently in Host mode dwc2 f72c0000.usb: Mode Mismatch Interrupt: currently in Host mode dwc2 f72c0000.usb: Mode Mismatch Interrupt: currently in Host mode dwc2 f72c0000.usb: Mode Mismatch Interrupt: currently in Host mode dwc2 f72c0000.usb: Mode Mismatch Interrupt: currently in Host mode init: Service 'adbd' (pid 1915) killed by signal 9 init: Sending signal 9 to service 'adbd' (pid 1915) process group... init: Successfully killed process cgroup uid 0 pid 1915 in 0ms init: processing action (init.svc.adbd=stopped) from (/init.usb.configfs.rc:15) dwc2 f72c0000.usb: dwc2_hc_chhltd_intr_dma: Channel 8 - ChHltd set, but reason is unknown dwc2 f72c0000.usb: hcint 0x00000002, intsts 0x04200029 dwc2 f72c0000.usb: dwc2_hc_chhltd_intr_dma: Channel 12 - ChHltd set, but reason is unknown dwc2 f72c0000.usb: hcint 0x00000002, intsts 0x04200029 dwc2 f72c0000.usb: dwc2_hc_chhltd_intr_dma: Channel 15 - ChHltd set, but reason is unknown dwc2 f72c0000.usb: hcint 0x00000002, intsts 0x04200029 dwc2 f72c0000.usb: dwc2_hc_chhltd_intr_dma: Channel 3 - ChHltd set, but reason is unknown dwc2 f72c0000.usb: hcint 0x00000002, intsts 0x04200029 dwc2 f72c0000.usb: dwc2_hc_chhltd_intr_dma: Channel 4 - ChHltd set, but reason is unknown dwc2 f72c0000.usb: hcint 0x00000002, intsts 0x04200029 dwc2 f72c0000.usb: dwc2_update_urb_state_abn(): trimming xfer length And the usb devices connected are basically hung at this point. It seems like if we're in host mode, we probably shouldn't run the dwc2_hostg_ep_disable logic, so this patch returns an error in that case. With this patch (along with the two previous patches mailed out earlier: https://lkml.org/lkml/2017/8/3/1008 https://lkml.org/lkml/2017/8/3/1010 ), we avoid the mismatched interrupts and connected usb devices continue to function. I'm not sure if some other solution would be better here, but this seems to work, so I wanted to send it out for input on what the right approach should be. Cc: Wei Xu <xuwei5@xxxxxxxxxxxxx> Cc: Guodong Xu <guodong.xu@xxxxxxxxxx> Cc: Amit Pundir <amit.pundir@xxxxxxxxxx> Cc: YongQin Liu <yongqin.liu@xxxxxxxxxx> Cc: John Youn <johnyoun@xxxxxxxxxxxx> Cc: Minas Harutyunyan <Minas.Harutyunyan@xxxxxxxxxxxx> Cc: Douglas Anderson <dianders@xxxxxxxxxxxx> Cc: Chen Yu <chenyu56@xxxxxxxxxx> Cc: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: linux-usb@xxxxxxxxxxxxxxx Reported-by: YongQin Liu <yongqin.liu@xxxxxxxxxx> Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx> --- drivers/usb/dwc2/gadget.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c index 0d8e09c..7fd0e38 100644 --- a/drivers/usb/dwc2/gadget.c +++ b/drivers/usb/dwc2/gadget.c @@ -4004,6 +4004,11 @@ static int dwc2_hsotg_ep_disable(struct usb_ep *ep) return -EINVAL; } + if (hsotg->op_state != OTG_STATE_B_PERIPHERAL) { + dev_err(hsotg->dev, "%s: called in host mode?\n", __func__); + return -EINVAL; + } + epctrl_reg = dir_in ? DIEPCTL(index) : DOEPCTL(index); spin_lock_irqsave(&hsotg->lock, flags); -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
