[PATCH 3.16 031/294] usb: renesas_usbhs: gadget: disable all eps when the driver stops

[Ben Hutchings]

3.16.50-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Yoshihiro Shimoda <yoshihiro.shimoda...@renesas.com>

commit b8b9c974afee685789fcbb191b52d1790be3608c upstream.

A gadget driver will not disable eps immediately when ->disconnect()
is called. But, since this driver assumes all eps stop after
the ->disconnect(), unexpected behavior happens (especially in system
suspend).
So, this patch disables all eps in usbhsg_try_stop(). After disabling
eps by renesas_usbhs driver, since some functions will be called by
both a gadget and renesas_usbhs driver, renesas_usbhs driver should
protect uep->pipe. To protect uep->pipe easily, this patch adds a new
lock in struct usbhsg_uep.

Fixes: 2f98382dc ("usb: renesas_usbhs: Add Renesas USBHS Gadget")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda...@renesas.com>
Signed-off-by: Felipe Balbi <felipe.ba...@linux.intel.com>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
 drivers/usb/renesas_usbhs/mod_gadget.c | 31 ++++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)

--- a/drivers/usb/renesas_usbhs/mod_gadget.c
+++ b/drivers/usb/renesas_usbhs/mod_gadget.c
@@ -36,6 +36,7 @@ struct usbhsg_gpriv;
 struct usbhsg_uep {
        struct usb_ep            ep;
        struct usbhs_pipe       *pipe;
+       spinlock_t              lock;   /* protect the pipe */
 
        char ep_name[EP_NAME_SIZE];
 
@@ -608,10 +609,16 @@ usbhsg_ep_enable_end:
 static int usbhsg_ep_disable(struct usb_ep *ep)
 {
        struct usbhsg_uep *uep = usbhsg_ep_to_uep(ep);
-       struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);
+       struct usbhs_pipe *pipe;
+       unsigned long flags;
+       int ret = 0;
 
-       if (!pipe)
-               return -EINVAL;
+       spin_lock_irqsave(&uep->lock, flags);
+       pipe = usbhsg_uep_to_pipe(uep);
+       if (!pipe) {
+               ret = -EINVAL;
+               goto out;
+       }
 
        usbhsg_pipe_disable(uep);
        usbhs_pipe_free(pipe);
@@ -619,6 +626,9 @@ static int usbhsg_ep_disable(struct usb_
        uep->pipe->mod_private  = NULL;
        uep->pipe               = NULL;
 
+out:
+       spin_unlock_irqrestore(&uep->lock, flags);
+
        return 0;
 }
 
@@ -668,8 +678,11 @@ static int usbhsg_ep_dequeue(struct usb_
 {
        struct usbhsg_uep *uep = usbhsg_ep_to_uep(ep);
        struct usbhsg_request *ureq = usbhsg_req_to_ureq(req);
-       struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);
+       struct usbhs_pipe *pipe;
+       unsigned long flags;
 
+       spin_lock_irqsave(&uep->lock, flags);
+       pipe = usbhsg_uep_to_pipe(uep);
        if (pipe)
                usbhs_pkt_pop(pipe, usbhsg_ureq_to_pkt(ureq));
 
@@ -678,6 +691,7 @@ static int usbhsg_ep_dequeue(struct usb_
         * even if the pipe is NULL.
         */
        usbhsg_queue_pop(uep, ureq, -ECONNRESET);
+       spin_unlock_irqrestore(&uep->lock, flags);
 
        return 0;
 }
@@ -804,10 +818,10 @@ static int usbhsg_try_stop(struct usbhs_
 {
        struct usbhsg_gpriv *gpriv = usbhsg_priv_to_gpriv(priv);
        struct usbhs_mod *mod = usbhs_mod_get_current(priv);
-       struct usbhsg_uep *dcp = usbhsg_gpriv_to_dcp(gpriv);
+       struct usbhsg_uep *uep;
        struct device *dev = usbhs_priv_to_dev(priv);
        unsigned long flags;
-       int ret = 0;
+       int ret = 0, i;
 
        /********************  spin lock ********************/
        usbhs_lock(priv, flags);
@@ -839,7 +853,9 @@ static int usbhsg_try_stop(struct usbhs_
        usbhs_sys_set_test_mode(priv, 0);
        usbhs_sys_function_ctrl(priv, 0);
 
-       usbhsg_ep_disable(&dcp->ep);
+       /* disable all eps */
+       usbhsg_for_each_uep_with_dcp(uep, gpriv, i)
+               usbhsg_ep_disable(&uep->ep);
 
        dev_dbg(dev, "stop gadget\n");
 
@@ -959,6 +975,7 @@ int usbhs_mod_gadget_probe(struct usbhs_
                ret = -ENOMEM;
                goto usbhs_mod_gadget_probe_err_gpriv;
        }
+       spin_lock_init(&uep->lock);
 
        /*
         * CAUTION