diff options
| author |   Wesley Cheng <wcheng@codeaurora.org> | 2021-09-16 19:18:52 -0700 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-21 16:35:03 +0200 |
| commit | 8217f07a50236779880f13e87f99224cd9117f83 (patch) | |
| tree | b2818c1e342b8560abf1ff5bb713be38dd7a8ecf | |
| parent | usb: core: hcd: fix messages in usb_hcd_request_irqs() (diff) | |
| download | linux-dev-8217f07a50236779880f13e87f99224cd9117f83.tar.xz linux-dev-8217f07a50236779880f13e87f99224cd9117f83.zip | |
usb: dwc3: gadget: Avoid starting DWC3 gadget during UDC unbind
There is a race present where the DWC3 runtime resume runs in parallel
to the UDC unbind sequence. This will eventually lead to a possible
scenario where we are enabling the run/stop bit, without a valid
composition defined.
Thread#1 (handling UDC unbind):
usb_gadget_remove_driver()
-->usb_gadget_disconnect()
-->dwc3_gadget_pullup(0)
--> continue UDC unbind sequence
-->Thread#2 is running in parallel here
Thread#2 (handing next cable connect)
__dwc3_set_mode()
-->pm_runtime_get_sync()
-->dwc3_gadget_resume()
-->dwc->gadget_driver is NOT NULL yet
-->dwc3_gadget_run_stop(1)
--> _dwc3gadget_start()
...
Fix this by tracking the pullup disable routine, and avoiding resuming
of the DWC3 gadget. Once the UDC is re-binded, that will trigger the
pullup enable routine, which would handle enabling the DWC3 gadget.
Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
Link: https://lore.kernel.org/r/20210917021852.2037-1-wcheng@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/dwc3/core.h | 2 | ||||
| -rw-r--r-- | drivers/usb/dwc3/gadget.c | 4 |
2 files changed, 4 insertions, 2 deletions
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h index 324ca5f5e98d..ee854697c300 100644 --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h @@ -1032,6 +1032,7 @@ struct dwc3_scratchpad_array { * @tx_fifo_resize_max_num: max number of fifos allocated during txfifo resize * @hsphy_interface: "utmi" or "ulpi" * @connected: true when we're connected to a host, false otherwise + * @softconnect: true when gadget connect is called, false when disconnect runs * @delayed_status: true when gadget driver asks for delayed status * @ep0_bounced: true when we used bounce buffer * @ep0_expect_in: true when we expect a DATA IN transfer @@ -1252,6 +1253,7 @@ struct dwc3 { const char *hsphy_interface; unsigned connected:1; + unsigned softconnect:1; unsigned delayed_status:1; unsigned ep0_bounced:1; unsigned ep0_expect_in:1; diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 804b50548163..32e01885b211 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -2418,7 +2418,7 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on) int ret; is_on = !!is_on; - + dwc->softconnect = is_on; /* * Per databook, when we want to stop the gadget, if a control transfer * is still in process, complete it and get the core into setup phase. @@ -4352,7 +4352,7 @@ int dwc3_gadget_resume(struct dwc3 *dwc) { int ret; - if (!dwc->gadget_driver) + if (!dwc->gadget_driver || !dwc->softconnect) return 0; ret = __dwc3_gadget_start(dwc); |