linux-kernel - [PATCH 1/2] usb: gadget: f_fs: edit epfile->ep under lock

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Date:   Tue,  4 Oct 2016 02:07:33 +0200
From:   Michal Nazarewicz <mina86@...a86.com>
To:     Chen Yu <chenyu56@...wei.com>,
        Felipe Balbi <felipe.balbi@...ux.intel.com>,
        John Stultz <john.stultz@...aro.org>
Cc:     Greg KH <gregkh@...uxfoundation.org>,
        Biggo Wang <wangbinghui@...ilicon.com>,
        Amit Pundir <amit.pundir@...aro.org>,
        Guodong Xu <guodong.xu@...aro.org>,
        linux-kernel@...r.kernel.org, linux-usb@...r.kernel.org,
        Michal Nazarewicz <mina86@...a86.com>
Subject: [PATCH 1/2] usb: gadget: f_fs: edit epfile->ep under lock

epfile->ep is protected by ffs->eps_lock (not epfile->mutex) so clear it
while holding the spin lock.

Signed-off-by: Michal Nazarewicz <mina86@...a86.com>
---
 drivers/usb/gadget/function/f_fs.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 0aeed85..759f5d4 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -1725,17 +1725,17 @@ static void ffs_func_eps_disable(struct ffs_function *func)
 	unsigned long flags;
 
 	do {
-		if (epfile)
-			mutex_lock(&epfile->mutex);
 		spin_lock_irqsave(&func->ffs->eps_lock, flags);
 		/* pending requests get nuked */
 		if (likely(ep->ep))
 			usb_ep_disable(ep->ep);
 		++ep;
+		if (epfile)
+			epfile->ep = NULL;
 		spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
 
 		if (epfile) {
-			epfile->ep = NULL;
+			mutex_lock(&epfile->mutex);
 			kfree(epfile->read_buffer);
 			epfile->read_buffer = NULL;
 			mutex_unlock(&epfile->mutex);
-- 
2.8.0.rc3.226.g39d4020