Merge branch 'drm-tda998x-3.12-fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-cubox...

[platform/adaptation/renesas_rcar/renesas_kernel.git] / sound / usb / endpoint.c

diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index b9ba0fc..83aabea 100644 (file)
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -636,8 +636,22 @@ static int data_ep_set_params(struct snd_usb_endpoint *ep,
        if (usb_pipein(ep->pipe) ||
                        snd_usb_endpoint_implicit_feedback_sink(ep)) {
 
+               urb_packs = packs_per_ms;
+               /*
+                * Wireless devices can poll at a max rate of once per 4ms.
+                * For dataintervals less than 5, increase the packet count to
+                * allow the host controller to use bursting to fill in the
+                * gaps.
+                */
+               if (snd_usb_get_speed(ep->chip->dev) == USB_SPEED_WIRELESS) {
+                       int interval = ep->datainterval;
+                       while (interval < 5) {
+                               urb_packs <<= 1;
+                               ++interval;
+                       }
+               }
                /* make capture URBs <= 1 ms and smaller than a period */
-               urb_packs = min(max_packs_per_urb, packs_per_ms);
+               urb_packs = min(max_packs_per_urb, urb_packs);
                while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
                        urb_packs >>= 1;
                ep->nurbs = MAX_URBS;