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@xxxxxxxxxxxxxxx> know about it. >From 0a2ce62b61f2c76d0213edf4e37aaf54a8ddf295 Mon Sep 17 00:00:00 2001 From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> 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@xxxxxxxxxxx> 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@xxxxxxxxxxx> Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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@xxxxxxxxxxx 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