[PATCH 3/5] usb: gadget: udc: renesas_usb3: lock for PN_ registers access

[Yoshihiro Shimoda]

This controller disallows to change the PIPE until reading/writing
a packet finishes. However. the previous code is not enough to hold
the lock in some functions. So, this patch fixes it.

Fixes: 746bfe63bba3 ("usb: gadget: renesas_usb3: add support for Renesas USB3.0 
peripheral controller")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda...@renesas.com>
---
 drivers/usb/gadget/udc/renesas_usb3.c | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/gadget/udc/renesas_usb3.c 
b/drivers/usb/gadget/udc/renesas_usb3.c
index e27d948..c05097b 100644
--- a/drivers/usb/gadget/udc/renesas_usb3.c
+++ b/drivers/usb/gadget/udc/renesas_usb3.c
@@ -1475,7 +1475,13 @@ static void usb3_request_done_pipen(struct renesas_usb3 
*usb3,
                                    struct renesas_usb3_request *usb3_req,
                                    int status)
 {
-       usb3_pn_stop(usb3);
+       unsigned long flags;
+
+       spin_lock_irqsave(&usb3->lock, flags);
+       if (usb3_pn_change(usb3, usb3_ep->num))
+               usb3_pn_stop(usb3);
+       spin_unlock_irqrestore(&usb3->lock, flags);
+
        usb3_disable_pipe_irq(usb3, usb3_ep->num);
        usb3_request_done(usb3_ep, usb3_req, status);
 
@@ -1504,30 +1510,46 @@ static void usb3_irq_epc_pipen_bfrdy(struct 
renesas_usb3 *usb3, int num)
 {
        struct renesas_usb3_ep *usb3_ep = usb3_get_ep(usb3, num);
        struct renesas_usb3_request *usb3_req = usb3_get_request(usb3_ep);
+       bool done = false;
 
        if (!usb3_req)
                return;
 
+       spin_lock(&usb3->lock);
+       if (usb3_pn_change(usb3, num))
+               goto out;
+
        if (usb3_ep->dir_in) {
                /* Do not stop the IN pipe here to detect LSTTR interrupt */
                if (!usb3_write_pipe(usb3_ep, usb3_req, USB3_PN_WRITE))
                        usb3_clear_bit(usb3, PN_INT_BFRDY, USB3_PN_INT_ENA);
        } else {
                if (!usb3_read_pipe(usb3_ep, usb3_req, USB3_PN_READ))
-                       usb3_request_done_pipen(usb3, usb3_ep, usb3_req, 0);
+                       done = true;
        }
+
+out:
+       /* need to unlock because usb3_request_done_pipen() locks it */
+       spin_unlock(&usb3->lock);
+
+       if (done)
+               usb3_request_done_pipen(usb3, usb3_ep, usb3_req, 0);
 }
 
 static void usb3_irq_epc_pipen(struct renesas_usb3 *usb3, int num)
 {
        u32 pn_int_sta;
 
-       if (usb3_pn_change(usb3, num) < 0)
+       spin_lock(&usb3->lock);
+       if (usb3_pn_change(usb3, num) < 0) {
+               spin_unlock(&usb3->lock);
                return;
+       }
 
        pn_int_sta = usb3_read(usb3, USB3_PN_INT_STA);
        pn_int_sta &= usb3_read(usb3, USB3_PN_INT_ENA);
        usb3_write(usb3, pn_int_sta, USB3_PN_INT_STA);
+       spin_unlock(&usb3->lock);
        if (pn_int_sta & PN_INT_LSTTR)
                usb3_irq_epc_pipen_lsttr(usb3, num);
        if (pn_int_sta & PN_INT_BFRDY)
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html