[PATCH 4.9 32/60] usb: gadget: udc: renesas_usb3: lock for PN_ registers access

Greg Kroah-Hartman
2017-06-19T16:04:13Z

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

commit 940f538a100c84c6e72813e4ac88bd1753a86945 upstream.

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.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/usb/gadget/udc/renesas_usb3.c | 28 +++++++++++++++++++++++++---
1 file changed, 25 insertions(+), 3 deletions(-)

--- a/drivers/usb/gadget/udc/renesas_usb3.c
+++ b/drivers/usb/gadget/udc/renesas_usb3.c
@@ -1401,7 +1401,13 @@ static void usb3_request_done_pipen(stru
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);

@@ -1430,30 +1436,46 @@ static void usb3_irq_epc_pipen_bfrdy(str
{
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)