[PATCH 4.9 034/206] usb: dwc3: core: avoid Overflow events

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

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

From: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>

commit e71d363d9c611c99fb78f53bfee99616e7fe352c upstream.

Now that we're handling so many transfers at a time
and for some dwc3 revisions LPM events *must* be
enabled, we can fall into a situation where too many
events fire and we start receiving Overflow events.

Let's do what XHCI does and allocate a full page for
the Event Ring, this will avoid any future issues.

Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/dwc3/core.h |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -43,9 +43,7 @@
 #define DWC3_XHCI_RESOURCES_NUM	2
 
 #define DWC3_SCRATCHBUF_SIZE	4096	/* each buffer is assumed to be 4KiB */
-#define DWC3_EVENT_SIZE		4	/* bytes */
-#define DWC3_EVENT_MAX_NUM	64	/* 2 events/endpoint */
-#define DWC3_EVENT_BUFFERS_SIZE	(DWC3_EVENT_SIZE * DWC3_EVENT_MAX_NUM)
+#define DWC3_EVENT_BUFFERS_SIZE	4096
 #define DWC3_EVENT_TYPE_MASK	0xfe
 
 #define DWC3_EVENT_TYPE_DEV	0