From: Kazuya Mizuguchi Date: Mon, 2 Oct 2017 05:01:41 +0000 (+0900) Subject: usb: renesas_usbhs: Fix DMAC sequence for receiving zero-length packet X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=767121581507749d66fe5212b9947083384d42d3;p=pandora-kernel.git usb: renesas_usbhs: Fix DMAC sequence for receiving zero-length packet commit 29c7f3e68eec4ae94d85ad7b5dfdafdb8089f513 upstream. 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") Signed-off-by: Yoshihiro Shimoda Signed-off-by: Felipe Balbi [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- diff --git a/drivers/usb/renesas_usbhs/fifo.c b/drivers/usb/renesas_usbhs/fifo.c index 897a2fc96397..c47ba7288433 100644 --- a/drivers/usb/renesas_usbhs/fifo.c +++ b/drivers/usb/renesas_usbhs/fifo.c @@ -817,8 +817,8 @@ static void usbhsf_dma_prepare_tasklet(unsigned long data) dev_dbg(dev, " %s %d (%d/ %d)\n", fifo->name, usbhs_pipe_number(pipe), pkt->length, pkt->zero); - usbhsf_dma_start(pipe, fifo); dma_async_issue_pending(chan); + usbhsf_dma_start(pipe, fifo); xfer_work_end: usbhs_unlock(priv, flags);