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From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Felipe Balbi <balbi@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Linus Walleij <linus.walleij@linaro.org>,
	Iago Abal <mail@iagoabal.eu>
Subject: [PATCH v1 3/6] usb: gadget: pch_udc: Revert d3cb25a12138 completely
Date: Mon, 22 Mar 2021 23:11:46 +0200	[thread overview]
Message-ID: <20210322211149.6658-3-andriy.shevchenko@linux.intel.com> (raw)
In-Reply-To: <20210322211149.6658-1-andriy.shevchenko@linux.intel.com>

The commit d3cb25a12138 ("usb: gadget: udc: fix spin_lock in pch_udc")
obviously was not thought through and had made the situation even worse
than it was before. Two changes after almost reverted it. but a few
leftovers have been left as it. With this revert d3cb25a12138 completely.

While at it, narrow down the scope of unlocked section to prevent
potential race when prot_stall is assigned.

Fixes: d3cb25a12138 ("usb: gadget: udc: fix spin_lock in pch_udc")
Fixes: 9903b6bedd38 ("usb: gadget: pch-udc: fix lock")
Fixes: 1d23d16a88e6 ("usb: gadget: pch_udc: reorder spin_[un]lock to avoid deadlock")
Cc: Iago Abal <mail@iagoabal.eu>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/usb/gadget/udc/pch_udc.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/gadget/udc/pch_udc.c b/drivers/usb/gadget/udc/pch_udc.c
index 5bb83a2705ad..5421075df01c 100644
--- a/drivers/usb/gadget/udc/pch_udc.c
+++ b/drivers/usb/gadget/udc/pch_udc.c
@@ -596,18 +596,22 @@ static void pch_udc_reconnect(struct pch_udc_dev *dev)
 static inline void pch_udc_vbus_session(struct pch_udc_dev *dev,
 					  int is_active)
 {
+	unsigned long		iflags;
+
+	spin_lock_irqsave(&dev->lock, iflags);
 	if (is_active) {
 		pch_udc_reconnect(dev);
 		dev->vbus_session = 1;
 	} else {
 		if (dev->driver && dev->driver->disconnect) {
-			spin_lock(&dev->lock);
+			spin_unlock_irqrestore(&dev->lock, iflags);
 			dev->driver->disconnect(&dev->gadget);
-			spin_unlock(&dev->lock);
+			spin_lock_irqsave(&dev->lock, iflags);
 		}
 		pch_udc_set_disconnect(dev);
 		dev->vbus_session = 0;
 	}
+	spin_unlock_irqrestore(&dev->lock, iflags);
 }
 
 /**
@@ -1166,20 +1170,25 @@ static int pch_udc_pcd_selfpowered(struct usb_gadget *gadget, int value)
 static int pch_udc_pcd_pullup(struct usb_gadget *gadget, int is_on)
 {
 	struct pch_udc_dev	*dev;
+	unsigned long		iflags;
 
 	if (!gadget)
 		return -EINVAL;
+
 	dev = container_of(gadget, struct pch_udc_dev, gadget);
+
+	spin_lock_irqsave(&dev->lock, iflags);
 	if (is_on) {
 		pch_udc_reconnect(dev);
 	} else {
 		if (dev->driver && dev->driver->disconnect) {
-			spin_lock(&dev->lock);
+			spin_unlock_irqrestore(&dev->lock, iflags);
 			dev->driver->disconnect(&dev->gadget);
-			spin_unlock(&dev->lock);
+			spin_lock_irqsave(&dev->lock, iflags);
 		}
 		pch_udc_set_disconnect(dev);
 	}
+	spin_unlock_irqrestore(&dev->lock, iflags);
 
 	return 0;
 }
-- 
2.30.2


  parent reply	other threads:[~2021-03-22 21:12 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-22 21:11 [PATCH v1 1/6] usb: gadget: pch_udc: Drop unneeded cpu_to_le32() call Andy Shevchenko
2021-03-22 21:11 ` [PATCH v1 2/6] usb: gardet: pch_udc: Check if driver is present before calling ->setup() Andy Shevchenko
2021-03-22 21:11 ` Andy Shevchenko [this message]
2021-03-22 21:11 ` [PATCH v1 4/6] usb: gadget: pch_udc: Move pch_udc_init() to satisfy kernel doc Andy Shevchenko
2021-03-23  9:45   ` Sergei Shtylyov
2021-03-23 10:35     ` Andy Shevchenko
2021-03-22 21:11 ` [PATCH v1 5/6] usb: gadget: pch_udc: Initialize device pointer before use Andy Shevchenko
2021-03-22 21:11 ` [PATCH v1 6/6] usb: gadget: pch_udc: Provide a GPIO line used on Intel Minnowboard (v1) Andy Shevchenko
2021-03-25  8:17   ` Linus Walleij
2021-03-23 11:58 ` [PATCH v1 1/6] usb: gadget: pch_udc: Drop unneeded cpu_to_le32() call Greg Kroah-Hartman
2021-03-23 12:24   ` Andy Shevchenko

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