Patch "usb: renesas_usbhs: fix usbhsf_fifo_clear() for RX direction" has been added to the 3.18-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    usb: renesas_usbhs: fix usbhsf_fifo_clear() for RX direction

to the 3.18-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     usb-renesas_usbhs-fix-usbhsf_fifo_clear-for-rx-direction.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 0a2ce62b61f2c76d0213edf4e37aaf54a8ddf295 Mon Sep 17 00:00:00 2001
From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Date: Wed, 27 Sep 2017 18:47:13 +0900
Subject: usb: renesas_usbhs: fix usbhsf_fifo_clear() for RX direction

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

commit 0a2ce62b61f2c76d0213edf4e37aaf54a8ddf295 upstream.

This patch fixes an issue that the usbhsf_fifo_clear() is possible
to cause 10 msec delay if the pipe is RX direction and empty because
the FRDY bit will never be set to 1 in such case.

Fixes: e8d548d54968 ("usb: renesas_usbhs: fifo became independent from pipe.")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/renesas_usbhs/fifo.c |   13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

--- a/drivers/usb/renesas_usbhs/fifo.c
+++ b/drivers/usb/renesas_usbhs/fifo.c
@@ -289,8 +289,17 @@ static void usbhsf_fifo_clear(struct usb
 	struct usbhs_priv *priv = usbhs_pipe_to_priv(pipe);
 	int ret = 0;
 
-	if (!usbhs_pipe_is_dcp(pipe))
-		ret = usbhsf_fifo_barrier(priv, fifo);
+	if (!usbhs_pipe_is_dcp(pipe)) {
+		/*
+		 * This driver checks the pipe condition first to avoid -EBUSY
+		 * from usbhsf_fifo_barrier() with about 10 msec delay in
+		 * the interrupt handler if the pipe is RX direction and empty.
+		 */
+		if (usbhs_pipe_is_dir_in(pipe))
+			ret = usbhs_pipe_is_accessible(pipe);
+		if (!ret)
+			ret = usbhsf_fifo_barrier(priv, fifo);
+	}
 
 	/*
 	 * if non-DCP pipe, this driver should set BCLR when


Patches currently in stable-queue which might be from yoshihiro.shimoda.uh@renesas.com are

queue-3.18/usb-renesas_usbhs-fix-usbhsf_fifo_clear-for-rx-direction.patch
queue-3.18/usb-renesas_usbhs-fix-the-bclr-setting-condition-for-non-dcp-pipe.patch