usb: dwc3: gadget: don't rely on jiffies while holding spinlock
__dwc3_gadget_wakeup() is called while holding a spinlock, then depends on
jiffies in order to timeout while polling the USB core for a link state
update. In the case the wakeup failed, the timeout will never happen and
will also cause the cpu to stall until rcu_preempt kicks in.
This switches to a "decrement variable and wait" timeout scheme.
Signed-off-by: Nicolas Saenz Julienne <nicolassaenzj@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 1f5597e..122e64d 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1433,7 +1433,7 @@
static int __dwc3_gadget_wakeup(struct dwc3 *dwc)
{
- unsigned long timeout;
+ int retries;
int ret;
u32 reg;
@@ -1484,9 +1484,9 @@
}
/* poll until Link State changes to ON */
- timeout = jiffies + msecs_to_jiffies(100);
+ retries = 20000;
- while (!time_after(jiffies, timeout)) {
+ while (retries--) {
reg = dwc3_readl(dwc->regs, DWC3_DSTS);
/* in HS, means ON */