From 29c7f3e68eec4ae94d85ad7b5dfdafdb8089f513 Mon Sep 17 00:00:00 2001 From: Kazuya Mizuguchi Date: Mon, 2 Oct 2017 14:01:41 +0900 Subject: [PATCH] usb: renesas_usbhs: Fix DMAC sequence for receiving zero-length packet The DREQE bit of the DnFIFOSEL should be set to 1 after the DE bit of USB-DMAC on R-Car SoCs is set to 1 after the USB-DMAC received a zero-length packet. Otherwise, a transfer completion interruption of USB-DMAC doesn't happen. Even if the driver changes the sequence, normal operations (transmit/receive without zero-length packet) will not cause any side-effects. So, this patch fixes the sequence anyway. Signed-off-by: Kazuya Mizuguchi [shimoda: revise the commit log] Fixes: e73a9891b3a1 ("usb: renesas_usbhs: add DMAEngine support") Cc: # v3.1+ Signed-off-by: Yoshihiro Shimoda Signed-off-by: Felipe Balbi --- drivers/usb/renesas_usbhs/fifo.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/renesas_usbhs/fifo.c b/drivers/usb/renesas_usbhs/fifo.c index 68f26904c316..50285b01da92 100644 --- a/drivers/usb/renesas_usbhs/fifo.c +++ b/drivers/usb/renesas_usbhs/fifo.c @@ -857,9 +857,9 @@ static void xfer_work(struct work_struct *work) fifo->name, usbhs_pipe_number(pipe), pkt->length, pkt->zero); usbhs_pipe_running(pipe, 1); - usbhsf_dma_start(pipe, fifo); usbhs_pipe_set_trans_count_if_bulk(pipe, pkt->trans); dma_async_issue_pending(chan); + usbhsf_dma_start(pipe, fifo); usbhs_pipe_enable(pipe); xfer_work_end: -- 2.20.1