usb: musb: cppi41: don't check early-TX-interrupt for Isoch transfer

[firefly-linux-kernel-4.4.55.git] / drivers / usb / musb / musb_cppi41.c

diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c
index e499b862a946f16ff8a8c7fc4694c4da93fd4c74..88f26ac2a185ba5cd9c430df97d81fbaef3ad3ff 100644 (file)
--- a/drivers/usb/musb/musb_cppi41.c
+++ b/drivers/usb/musb/musb_cppi41.c
@@ -250,8 +250,27 @@ static void cppi41_dma_callback(void *private_data)
                        transferred < cppi41_channel->packet_sz)
                cppi41_channel->prog_len = 0;
 
-       if (cppi41_channel->is_tx)
-               empty = musb_is_tx_fifo_empty(hw_ep);
+       if (cppi41_channel->is_tx) {
+               u8 type;
+
+               if (is_host_active(musb))
+                       type = hw_ep->out_qh->type;
+               else
+                       type = hw_ep->ep_in.type;
+
+               if (type == USB_ENDPOINT_XFER_ISOC)
+                       /*
+                        * Don't use the early-TX-interrupt workaround below
+                        * for Isoch transfter. Since Isoch are periodic
+                        * transfer, by the time the next transfer is
+                        * scheduled, the current one should be done already.
+                        *
+                        * This avoids audio playback underrun issue.
+                        */
+                       empty = true;
+               else
+                       empty = musb_is_tx_fifo_empty(hw_ep);
+       }
 
        if (!cppi41_channel->is_tx || empty) {
                cppi41_trans_done(cppi41_channel);