4.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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);