[PATCH 1/3] usb: dwc2: Improve gadget state disconnection handling

[PATCH 1/3] usb: dwc2: Improve gadget state disconnection handling

[John Stultz]

In the earlier commit dad3f793f20f ("usb: dwc2: Make sure we
disconnect the gadget state"), I was trying to fix up the
fact that we somehow weren't disconnecting the gadget state,
so that when the OTG port was plugged in the second time we
would get warnings about the state tracking being wrong.

The fix there was somewhat simple, as it just made sure to
call dwc2_hsotg_disconnect() before we connected things up
in OTG mode.

But in looking at a different issue I was seeing with UDC
state handling, I realized that it would be much better
to call dwc2_hsotg_disconnect when we get the state change
signal moving to host mode.

Thus, this patch removes the earlier disconnect call I added
and moves it (and the needed locking) to the host mode
transition.

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
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 drivers/usb/dwc2/hcd.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index 740c7e8..9fd84a9 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -3277,7 +3277,6 @@ static void dwc2_conn_id_status_change(struct work_struct *work)
 		dwc2_core_init(hsotg, false);
 		dwc2_enable_global_interrupts(hsotg);
 		spin_lock_irqsave(&hsotg->lock, flags);
-		dwc2_hsotg_disconnect(hsotg);
 		dwc2_hsotg_core_init_disconnected(hsotg, false);
 		spin_unlock_irqrestore(&hsotg->lock, flags);
 		dwc2_hsotg_core_connect(hsotg);
@@ -3296,8 +3295,13 @@ static void dwc2_conn_id_status_change(struct work_struct *work)
 		if (count > 250)
 			dev_err(hsotg->dev,
 				"Connection id status change timed out\n");
-		hsotg->op_state = OTG_STATE_A_HOST;
 
+		spin_lock_irqsave(&hsotg->lock, flags);
+		dwc2_hsotg_disconnect(hsotg);
+		dwc2_hsotg_core_init_disconnected(hsotg, false);
+		spin_unlock_irqrestore(&hsotg->lock, flags);
+
+		hsotg->op_state = OTG_STATE_A_HOST;
 		/* Initialize the Core for Host mode */
 		dwc2_core_init(hsotg, false);
 		dwc2_enable_global_interrupts(hsotg);
-- 
2.7.4

[PATCH 2/3] usb: dwc2: Fix UDC state tracking

[John Stultz]

It has been noticed that the dwc2 udc state reporting doesn't
seem to work (at least on HiKey boards). Where after the initial
setup, the sysfs /sys/class/udc/f72c0000.usb/state file would
report "configured" no matter the state of the OTG port.

This patch adds a call so that we report to the UDC layer when
the gadget device is disconnected.

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
Reported-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 drivers/usb/dwc2/gadget.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index c4066cd..e6f2cd8 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -3202,6 +3202,8 @@ void dwc2_hsotg_disconnect(struct dwc2_hsotg *hsotg)
 
 	call_gadget(hsotg, disconnect);
 	hsotg->lx_state = DWC2_L3;
+
+	usb_gadget_set_state(&hsotg->gadget, USB_STATE_NOTATTACHED);
 }
 
 /**
-- 
2.7.4

[PATCH 3/3] usb: dwc2: Error out of dwc2_hsotg_ep_disable() if we're in host mode

[John Stultz]

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@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
Reported-by: YongQin Liu <yongqin.liu@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 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 e6f2cd8..61fb76f 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -4006,6 +4006,11 @@ 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

Re: [PATCH 1/3] usb: dwc2: Improve gadget state disconnection handling

[John Stultz]

On Thu, Aug 17, 2017 at 12:03 PM, John Stultz <john.stultz@linaro.org> wrote:
> In the earlier commit dad3f793f20f ("usb: dwc2: Make sure we
> disconnect the gadget state"), I was trying to fix up the
> fact that we somehow weren't disconnecting the gadget state,
> so that when the OTG port was plugged in the second time we
> would get warnings about the state tracking being wrong.
>
> The fix there was somewhat simple, as it just made sure to
> call dwc2_hsotg_disconnect() before we connected things up
> in OTG mode.
>
> But in looking at a different issue I was seeing with UDC
> state handling, I realized that it would be much better
> to call dwc2_hsotg_disconnect when we get the state change
> signal moving to host mode.
>
> Thus, this patch removes the earlier disconnect call I added
> and moves it (and the needed locking) to the host mode
> transition.

Ping? I don't mean to be a bother, but any thoughts on this patchset?

thanks
-john

Re: [PATCH 1/3] usb: dwc2: Improve gadget state disconnection handling

[Felipe Balbi]

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Hi,

John Stultz <john.stultz@linaro.org> writes:
> On Thu, Aug 17, 2017 at 12:03 PM, John Stultz <john.stultz@linaro.org> wrote:
>> In the earlier commit dad3f793f20f ("usb: dwc2: Make sure we
>> disconnect the gadget state"), I was trying to fix up the
>> fact that we somehow weren't disconnecting the gadget state,
>> so that when the OTG port was plugged in the second time we
>> would get warnings about the state tracking being wrong.
>>
>> The fix there was somewhat simple, as it just made sure to
>> call dwc2_hsotg_disconnect() before we connected things up
>> in OTG mode.
>>
>> But in looking at a different issue I was seeing with UDC
>> state handling, I realized that it would be much better
>> to call dwc2_hsotg_disconnect when we get the state change
>> signal moving to host mode.
>>
>> Thus, this patch removes the earlier disconnect call I added
>> and moves it (and the needed locking) to the host mode
>> transition.
>
> Ping? I don't mean to be a bother, but any thoughts on this patchset?

I'm not taking patches which John hasn't acked, sorry.

-- 
balbi

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