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| author | Wesley Cheng <wcheng@codeaurora.org> | 2021-09-17 05:18:52 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-28 12:10:20 +0300 |
| commit | b83692feb09c1817674839f5b0ad68e630f61e51 (patch) | |
| tree | ac2dad5c0b4a7ea3875ab94f212a9ec8f0cba51d | |
| parent | 2a358ad19c3ef46cdc67f69ff4782c1c1fcfa7a7 (diff) | |
| download | linux-b83692feb09c1817674839f5b0ad68e630f61e51.tar.xz | |
usb: dwc3: gadget: Avoid starting DWC3 gadget during UDC unbind
[ Upstream commit 8217f07a50236779880f13e87f99224cd9117f83 ]
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>
Stable-dep-of: 040f2dbd2010 ("usb: dwc3: gadget: Avoid duplicate requests to enable Run/Stop")
Signed-off-by: Sasha Levin <sashal@kernel.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 79e1b82e5e05..1cb1601a6d98 100644 --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h @@ -1010,6 +1010,7 @@ struct dwc3_scratchpad_array { * @tx_max_burst_prd: max periodic ESS transmit burst size * @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 @@ -1218,6 +1219,7 @@ 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 a2a10c05ef3f..85a0159f12ec 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -2127,7 +2127,7 @@ 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. @@ -4048,7 +4048,7 @@ 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); |