4.4-stable review patch. If anyone has any objections, please let me know.
------------------
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
@@ -287,8 +287,17 @@ 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