linux/drivers/usb/dwc3
Wesley Cheng 02435a739b usb: dwc3: gadget: Stall and restart EP0 if host is unresponsive
It was observed that there are hosts that may complete pending SETUP
transactions before the stop active transfers and controller halt occurs,
leading to lingering endxfer commands on DEPs on subsequent pullup/gadget
start iterations.

  dwc3_gadget_ep_disable   name=ep8in flags=0x3009  direction=1
  dwc3_gadget_ep_disable   name=ep4in flags=1  direction=1
  dwc3_gadget_ep_disable   name=ep3out flags=1  direction=0
  usb_gadget_disconnect   deactivated=0  connected=0  ret=0

The sequence shows that the USB gadget disconnect (dwc3_gadget_pullup(0))
routine completed successfully, allowing for the USB gadget to proceed with
a USB gadget connect.  However, if this occurs the system runs into an
issue where:

  BUG: spinlock already unlocked on CPU
  spin_bug+0x0
  dwc3_remove_requests+0x278
  dwc3_ep0_out_start+0xb0
  __dwc3_gadget_start+0x25c

This is due to the pending endxfers, leading to gadget start (w/o lock
held) to execute the remove requests, which will unlock the dwc3
spinlock as part of giveback.

To mitigate this, resolve the pending endxfers on the pullup disable
path by re-locating the SETUP phase check after stop active transfers, since
that is where the DWC3_EP_DELAY_STOP is potentially set.  This also allows
for handling of a host that may be unresponsive by using the completion
timeout to trigger the stall and restart for EP0.

Fixes: c96683798e ("usb: dwc3: ep0: Don't prepare beyond Setup stage")
Cc: stable@vger.kernel.org
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
Link: https://lore.kernel.org/r/20230413195742.11821-2-quic_wcheng@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 11:20:00 +02:00
..
core.c usb: dwc3: core: add support for disabling High-speed park mode 2023-04-20 11:18:12 +02:00
core.h usb: dwc3: core: add support for disabling High-speed park mode 2023-04-20 11:18:12 +02:00
debug.h usb: dwc3: Add function suspend and function wakeup support 2023-03-29 10:27:01 +02:00
debugfs.c usb: dwc3: add several registers dump for debugfs 2023-03-23 19:19:23 +01:00
drd.c usb: dwc3: Don't switch OTG -> peripheral if extcon is present 2022-10-22 12:29:43 +02:00
dwc3-am62.c usb: Add explicit of.h of_platform.h include 2023-04-20 10:12:29 +02:00
dwc3-exynos.c usb: dwc3: exynos: Fix remove() function 2022-11-22 16:51:45 +01:00
dwc3-haps.c usb: dwc3: haps: Constify the software node 2021-02-04 15:42:06 +01:00
dwc3-imx8mp.c usb: dwc3: imx8mp: Add support for setting SOC specific flags 2022-03-15 15:37:11 +01:00
dwc3-keystone.c usb: dwc3: fix incorrect kernel-doc comment syntax in files 2021-04-02 15:20:51 +02:00
dwc3-meson-g12a.c usb: dwc3-meson-g12a: constify drvdata structs 2022-03-15 15:33:52 +01:00
dwc3-of-simple.c usb: dwc3: Add driver for Xilinx platforms 2021-03-23 12:48:14 +01:00
dwc3-omap.c usb: dwc3: omap: fix "unbalanced disables for smps10_out1" on omap5evm 2022-03-15 15:44:46 +01:00
dwc3-pci.c Merge 6.3-rc6 into usb-next 2023-04-10 08:56:59 +02:00
dwc3-qcom.c usb: dwc3: qcom: enable vbus override when in OTG dr-mode 2023-01-24 18:19:00 +01:00
dwc3-st.c usb: dwc3: st: Rely on child's compatible instead of name 2022-10-25 19:06:13 +02:00
dwc3-xilinx.c usb: dwc3: xilinx: Remove unused of_gpio,h 2023-02-16 12:45:30 +01:00
ep0.c usb: dwc3: Add function suspend and function wakeup support 2023-03-29 10:27:01 +02:00
gadget.c usb: dwc3: gadget: Stall and restart EP0 if host is unresponsive 2023-04-20 11:20:00 +02:00
gadget.h usb: dwc3: Fix ep0 handling when getting reset while doing control transfer 2022-05-19 18:14:16 +02:00
host.c usb: dwc3: host: remove dead code in dwc3_host_get_irq() 2023-03-29 09:02:25 +02:00
io.h usb: dwc3: fix incorrect kernel-doc comment syntax in files 2021-04-02 15:20:51 +02:00
Kconfig usb: dwc3: fix extcon dependency 2023-01-19 14:19:49 +01:00
Makefile drivers: usb: dwc3: Add AM62 USB wrapper driver 2022-04-21 18:31:56 +02:00
trace.c usb: dwc3: fix incorrect kernel-doc comment syntax in files 2021-04-02 15:20:51 +02:00
trace.h usb: dwc3: change some trace event __dynamic_array() to __get_buf() 2023-03-09 15:35:03 +01:00
ulpi.c usb: dwc3: ulpi: Fix USB2.0 HS/FS/LS PHY suspend regression 2020-12-28 15:55:44 +01:00