4.4-stable review patch. If anyone has any objections, please let me know.
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From: John Stultz john.stultz@linaro.org
[ Upstream commit 9b481092c2a31a6b630aff9c28f0145bf6683787 ]
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 previous patch in this set), 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@hisilicon.com Cc: Guodong Xu guodong.xu@linaro.org Cc: Amit Pundir amit.pundir@linaro.org Cc: YongQin Liu yongqin.liu@linaro.org Cc: John Youn johnyoun@synopsys.com Cc: Minas Harutyunyan Minas.Harutyunyan@synopsys.com Cc: Douglas Anderson dianders@chromium.org Cc: Chen Yu chenyu56@huawei.com Cc: Felipe Balbi felipe.balbi@linux.intel.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: linux-usb@vger.kernel.org Acked-by: Minas Harutyunyan hminas@synopsys.com Tested-by: Minas Harutyunyan hminas@synopsys.com Reported-by: YongQin Liu yongqin.liu@linaro.org Signed-off-by: John Stultz john.stultz@linaro.org Signed-off-by: Felipe Balbi felipe.balbi@linux.intel.com Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/dwc2/gadget.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/drivers/usb/dwc2/gadget.c +++ b/drivers/usb/dwc2/gadget.c @@ -2834,6 +2834,11 @@ static int dwc2_hsotg_ep_disable(struct 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);