Thread (65 messages) 65 messages, 5 authors, 2016-08-26

[PATCH v2 08/22] usb: chipidea: Remove locking in ci_udc_start()

From: Peter Chen <hidden>
Date: 2016-07-08 09:53:09
Also in: linux-arm-msm, lkml

On Thu, Jul 07, 2016 at 03:20:59PM -0700, Stephen Boyd wrote:
quoted hunk ↗ jump to hunk
We don't call hw_device_reset() with the ci->lock held, so it
doesn't seem like this lock here is protecting anything. Let's
just remove it. This allows us to call sleeping functions like
phy_init() from within the CI_HDRC_CONTROLLER_RESET_EVENT hook.

Cc: Peter Chen <redacted>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <redacted>
---
 drivers/usb/chipidea/udc.c | 3 ---
 1 file changed, 3 deletions(-)
diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
index 065f5d97aa67..f16be4710cdb 100644
--- a/drivers/usb/chipidea/udc.c
+++ b/drivers/usb/chipidea/udc.c
@@ -1719,7 +1719,6 @@ static int ci_udc_start(struct usb_gadget *gadget,
 			 struct usb_gadget_driver *driver)
 {
 	struct ci_hdrc *ci = container_of(gadget, struct ci_hdrc, gadget);
-	unsigned long flags;
 	int retval = -ENOMEM;
 
 	if (driver->disconnect == NULL)
@@ -1746,7 +1745,6 @@ static int ci_udc_start(struct usb_gadget *gadget,
 
 	pm_runtime_get_sync(&ci->gadget.dev);
 	if (ci->vbus_active) {
-		spin_lock_irqsave(&ci->lock, flags);
 		hw_device_reset(ci);
 	} else {
 		usb_udc_vbus_handler(&ci->gadget, false);
@@ -1755,7 +1753,6 @@ static int ci_udc_start(struct usb_gadget *gadget,
 	}
 
 	retval = hw_device_state(ci, ci->ep0out->qh.dma);
-	spin_unlock_irqrestore(&ci->lock, flags);
 	if (retval)
 		pm_runtime_put_sync(&ci->gadget.dev);
 
The main purpose for this is disabling interrupt when reset controller,
in case the unexpected interrupts occur.

You can move this between hw_device_state.

-- 

Best Regards,
Peter Chen
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