[PATCH 3.16 152/217] usb: renesas_usbhs: disable TX IRQ before starting TX DMAC transfer

[Ben Hutchings]

3.16.35-rc1 review patch.  If anyone has any objections, please let me know.

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

commit 6490865c67825277b29638e839850882600b48ec upstream.

This patch adds a code to surely disable TX IRQ of the pipe before
starting TX DMAC transfer. Otherwise, a lot of unnecessary TX IRQs
may happen in rare cases when DMAC is used.

Fixes: e73a989 ("usb: renesas_usbhs: add DMAEngine support")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda...@renesas.com>
Signed-off-by: Felipe Balbi <felipe.ba...@linux.intel.com>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
 drivers/usb/renesas_usbhs/fifo.c | 1 +
 1 file changed, 1 insertion(+)

--- a/drivers/usb/renesas_usbhs/fifo.c
+++ b/drivers/usb/renesas_usbhs/fifo.c
@@ -851,6 +851,7 @@ static int usbhsf_dma_prepare_push(struc
 
        pkt->trans = len;
 
+       usbhsf_tx_irq_ctrl(pipe, 0);
        INIT_WORK(&pkt->work, xfer_work);
        schedule_work(&pkt->work);