This is a note to let you know that I've just added the patch titled
usb: dwc3: of-simple: fix oops by unbalanced clk disable call
to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: usb-dwc3-of-simple-fix-oops-by-unbalanced-clk-disable-call.patch and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From bff52352e0ccc2481f2b6b0d612ff8ff56c50f3a Mon Sep 17 00:00:00 2001
From: Enric Balletbo i Serra enric.balletbo@collabora.com Date: Mon, 18 Dec 2017 16:14:36 +0100 Subject: usb: dwc3: of-simple: fix oops by unbalanced clk disable call
From: Enric Balletbo i Serra enric.balletbo@collabora.com
commit bff52352e0ccc2481f2b6b0d612ff8ff56c50f3a upstream.
dwc3_of_simple_dev_pm_ops has never been used since commit a0d8c4cfdf31 ("usb: dwc3: of-simple: set dev_pm_ops"), but this commit has brought and oops when unbind the device due this sequence:
dwc3_of_simple_remove -> clk_disable ... -> pm_runtime_put_sync -> dwc3_of_simple_runtime_suspend -> clk_disable (again)
This double call to clk_core_disable causes a kernel oops like this:
WARNING: CPU: 1 PID: 4022 at drivers/clk/clk.c:656 clk_core_disable+0x78/0x80 CPU: 1 PID: 4022 Comm: bash Not tainted 4.15.0-rc4+ #44 Hardware name: Google Kevin (DT) pstate: 80000085 (Nzcv daIf -PAN -UAO) pc : clk_core_disable+0x78/0x80 lr : clk_core_disable_lock+0x20/0x38 sp : ffff00000bbf3a90 ... Call trace: clk_core_disable+0x78/0x80 clk_disable+0x1c/0x30 dwc3_of_simple_runtime_suspend+0x30/0x50 pm_generic_runtime_suspend+0x28/0x40
This patch fixes the unbalanced clk disable call by setting the num_clocks variable to zero once the clocks were disabled.
Fixes: a0d8c4cfdf31 ("usb: dwc3: of-simple: set dev_pm_ops") Signed-off-by: Enric Balletbo i Serra enric.balletbo@collabora.com Signed-off-by: Felipe Balbi felipe.balbi@linux.intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/usb/dwc3/dwc3-of-simple.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/usb/dwc3/dwc3-of-simple.c +++ b/drivers/usb/dwc3/dwc3-of-simple.c @@ -143,6 +143,7 @@ static int dwc3_of_simple_remove(struct clk_disable_unprepare(simple->clks[i]); clk_put(simple->clks[i]); } + simple->num_clocks = 0;
reset_control_assert(simple->resets); reset_control_put(simple->resets);
Patches currently in stable-queue which might be from enric.balletbo@collabora.com are
queue-4.15/usb-dwc3-of-simple-fix-oops-by-unbalanced-clk-disable-call.patch