From: lyz <lyz@rock-chips.com>
Date: Mon, 19 Jan 2015 10:55:56 +0000 (+0800)
Subject: usb: dwc_otg: fix issue with race condition of competition
X-Git-Tag: firefly_0821_release~4279
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b1e25b6bf255cecf4d022099857d200cbc681661;p=firefly-linux-kernel-4.4.55.git

usb: dwc_otg: fix issue with race condition of competition
between hcd_reinit() and cil_interrupt handler.

hcd_reinit() should get core_if->lock before modify this
lock, so that can prevent competition between cil_interrupt
handler and hcd_reinit(), hcd_reinit() be scheduled while
cil_interrupt handler holding core_if->lock, hcd_reinit() modify
the lock then previous core_if->lock will never be unlocked.

Signed-off-by: lyz <lyz@rock-chips.com>
---

diff --git a/drivers/usb/dwc_otg_310/dwc_otg_hcd.c b/drivers/usb/dwc_otg_310/dwc_otg_hcd.c
index 451424e84204..7602e4f851f6 100755
--- a/drivers/usb/dwc_otg_310/dwc_otg_hcd.c
+++ b/drivers/usb/dwc_otg_310/dwc_otg_hcd.c
@@ -966,9 +966,9 @@ static void dwc_otg_hcd_reinit(dwc_otg_hcd_t *hcd)
 	dwc_hc_t *channel;
 	dwc_hc_t *channel_tmp;
 	dwc_irqflags_t flags;
+	dwc_spinlock_t *temp_lock;
 
 	hcd->flags.d32 = 0;
-
 	hcd->non_periodic_qh_ptr = &hcd->non_periodic_sched_active;
 	hcd->non_periodic_channels = 0;
 	hcd->periodic_channels = 0;
@@ -995,7 +995,15 @@ static void dwc_otg_hcd_reinit(dwc_otg_hcd_t *hcd)
 	dwc_otg_core_host_init(hcd->core_if);
 
 	/* Set core_if's lock pointer to the hcd->lock */
-	hcd->core_if->lock = hcd->lock;
+	/* Should get this lock before modify it */
+	if (hcd->core_if->lock) {
+		DWC_SPINLOCK_IRQSAVE(hcd->core_if->lock, &flags);
+		temp_lock = hcd->core_if->lock;
+		hcd->core_if->lock = hcd->lock;
+		DWC_SPINUNLOCK_IRQRESTORE(temp_lock, flags);
+	} else {
+		hcd->core_if->lock = hcd->lock;
+	}
 }
 
 /**