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authorJohn Stultz <john.stultz@linaro.org>2017-01-23 23:59:14 +0100
committerFelipe Balbi <felipe.balbi@linux.intel.com>2017-01-24 15:19:08 +0100
commit6e6360b67d12370638ad1bc8943cc63d4c89da27 (patch)
tree341fc06bd363a75182facd22292b6189bb6f885d /drivers/usb/dwc2/gadget.c
parentusb: dwc2: Show dr_mode via debugfs (diff)
downloadlinux-6e6360b67d12370638ad1bc8943cc63d4c89da27.tar.xz
linux-6e6360b67d12370638ad1bc8943cc63d4c89da27.zip
usb: dwc2: Avoid sleeping while holding hsotg->lock
Basically when plugging in various cables in different orders, I'm occasionally seeing the following BUG splat: [ 86.215403] BUG: scheduling while atomic: kworker/u16:2/53/0x00000002 [ 86.219164] usb 1-1: USB disconnect, device number 9 [ 86.226845] Preemption disabled at:[ 86.230218] [<ffffff8008673558>] dwc2_conn_id_status_change+0x120/0x250 [ 86.236894] CPU: 0 PID: 53 Comm: kworker/u16:2 Tainted: G W 4.9.0-rc8-00051-gd5a7979-dirty #1702 [ 86.246836] Hardware name: HiKey Development Board (DT) [ 86.252100] Workqueue: dwc2 dwc2_conn_id_status_change [ 86.257279] Call trace: [ 86.259771] [<ffffff8008087c28>] dump_backtrace+0x0/0x1a0 [ 86.265210] [<ffffff8008087ddc>] show_stack+0x14/0x20 [ 86.270308] [<ffffff80084343f0>] dump_stack+0x90/0xb0 [ 86.275401] [<ffffff80080d8d94>] __schedule_bug+0x6c/0xb8 [ 86.280841] [<ffffff8008a07220>] __schedule+0x4f8/0x5b0 [ 86.286099] [<ffffff8008a073e8>] schedule+0x38/0xa0 [ 86.291017] [<ffffff8008a0a6cc>] schedule_hrtimeout_range_clock+0x8c/0xf0 [ 86.297846] [<ffffff8008a0a740>] schedule_hrtimeout_range+0x10/0x18 [ 86.304150] [<ffffff8008a0a4a0>] usleep_range+0x50/0x58 [ 86.309418] [<ffffff800866d8dc>] dwc2_wait_for_mode.isra.4+0x54/0xd0 [ 86.315815] [<ffffff800866f058>] dwc2_core_reset+0xe0/0x168 [ 86.321431] [<ffffff800867e364>] dwc2_hsotg_core_init_disconnected+0x2c/0x310 [ 86.328602] [<ffffff8008673568>] dwc2_conn_id_status_change+0x130/0x250 [ 86.335254] [<ffffff80080ccd48>] process_one_work+0x118/0x370 [ 86.341035] [<ffffff80080ccfe8>] worker_thread+0x48/0x498 [ 86.346473] [<ffffff80080d2eb0>] kthread+0xd0/0xe8 [ 86.351299] [<ffffff8008082e80>] ret_from_fork+0x10/0x50 This seems to be caused by the dwc2_wait_for_mode() calling usleep_range() while the hstog->lock spinlock is held, since we take that before calling dwc2_hsotg_core_init_disconnected(). This patch avoids the issue by adding an extra argument to dwc2_core_reset(), as suggested by John Youn, which allows us to skip the waiting, which should be unnecessary when calling from dwc2_hsotg_core_init_disconnected(). Cc: Wei Xu <xuwei5@hisilicon.com> Cc: Guodong Xu <guodong.xu@linaro.org> Cc: Amit Pundir <amit.pundir@linaro.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: John Youn <johnyoun@synopsys.com> Cc: Douglas Anderson <dianders@chromium.org> Cc: Chen Yu <chenyu56@huawei.com> Cc: Vardan Mikayelyan <mvardan@synopsys.com> Cc: Kishon Vijay Abraham I <kishon@ti.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> Signed-off-by: John Youn <johnyoun@synopsys.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Diffstat (limited to '')
-rw-r--r--drivers/usb/dwc2/gadget.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 1a1355429c1a..30ff51eab35c 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -3164,7 +3164,7 @@ void dwc2_hsotg_core_init_disconnected(struct dwc2_hsotg *hsotg,
kill_all_requests(hsotg, hsotg->eps_out[0], -ECONNRESET);
if (!is_usb_reset)
- if (dwc2_core_reset(hsotg))
+ if (dwc2_core_reset(hsotg, true))
return;
/*