[PATCH 4.4 018/101] usb: dwc3: core: avoid Overflow events

From: Greg Kroah-Hartman
Date: Tue Jan 10 2017 - 10:20:34 EST


4.4-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
@@ -42,9 +42,7 @@
#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