With recent changes in AOSP, adb is using asynchronous io, which causes the following crash usually on a reboot:
[ 184.278302] BUG: scheduling while atomic: ksoftirqd/0/9/0x00000104 [ 184.284617] Modules linked in: wl18xx wlcore snd_soc_hdmi_codec wlcore_sdio tcpci_rt1711h tcpci tcpm typec adv7511 cec dwc3 phy_hi3660_usb3 snd_soc_simple_card snd_soc_a [ 184.316034] Preemption disabled at: [ 184.316072] [<ffffff8008081de4>] __do_softirq+0x64/0x398 [ 184.324953] CPU: 0 PID: 9 Comm: ksoftirqd/0 Tainted: G S 4.19.43-00669-g8e4970572c43-dirty #356 [ 184.334963] Hardware name: HiKey960 (DT) [ 184.338892] Call trace: [ 184.341352] dump_backtrace+0x0/0x158 [ 184.345025] show_stack+0x14/0x20 [ 184.348355] dump_stack+0x80/0xa4 [ 184.351685] __schedule_bug+0x6c/0xc0 [ 184.355363] __schedule+0x64c/0x978 [ 184.358863] schedule+0x2c/0x90 [ 184.362053] dwc3_gadget_ep_dequeue+0x274/0x388 [dwc3] [ 184.367210] usb_ep_dequeue+0x24/0xf8 [ 184.370884] ffs_aio_cancel+0x3c/0x80 [ 184.374561] free_ioctx_users+0x40/0x148 [ 184.378500] percpu_ref_switch_to_atomic_rcu+0x180/0x1c0 [ 184.383830] rcu_process_callbacks+0x24c/0x5d8 [ 184.388283] __do_softirq+0x13c/0x398 [ 184.391959] run_ksoftirqd+0x3c/0x48 [ 184.395549] smpboot_thread_fn+0x220/0x288 [ 184.399660] kthread+0x12c/0x130 [ 184.402901] ret_from_fork+0x10/0x1c
This happens as usb_ep_dequeue can be called in interrupt context, and dwc3_gadget_ep_dequeue() then calls wait_event_lock_irq() which can sleep.
Upstream kernels are not affected due to the change fec9095bdef4 ("dwc3: gadget: remove wait_end_transfer") which removes the wait_even_lock_irq code. Unfortunately that change has a number of dependencies, which I'm submitting here.
Also, to match upstream, in this series I've reverted one change that was backported to -stable, to replace it with the cherry-picked upstream commit (as the dependencies are now there)
This issue also affects 4.14,4.9 and I believe 4.4 kernels, however I don't know how to best backport this functionality that far back. Help from the maintainers would be very much appreciated!
Feedback and comments would be welcome!
thanks -john
Cc: Fei Yang fei.yang@intel.com Cc: Sam Protsenko semen.protsenko@linaro.org Cc: Felipe Balbi balbi@kernel.org Cc: linux-usb@vger.kernel.org Cc: stable@vger.kernel.org # 4.19.y
Felipe Balbi (7): usb: dwc3: gadget: combine unaligned and zero flags usb: dwc3: gadget: track number of TRBs per request usb: dwc3: gadget: use num_trbs when skipping TRBs on ->dequeue() usb: dwc3: gadget: extract dwc3_gadget_ep_skip_trbs() usb: dwc3: gadget: introduce cancelled_list usb: dwc3: gadget: move requests to cancelled_list usb: dwc3: gadget: remove wait_end_transfer
Jack Pham (1): usb: dwc3: gadget: Clear req->needs_extra_trb flag on cleanup
John Stultz (1): Revert "usb: dwc3: gadget: Clear req->needs_extra_trb flag on cleanup"
drivers/usb/dwc3/core.h | 15 ++-- drivers/usb/dwc3/gadget.c | 158 +++++++++++++------------------------- drivers/usb/dwc3/gadget.h | 15 ++++ 3 files changed, 75 insertions(+), 113 deletions(-)