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.") Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> Signed-off-by: Willy Tarreau <w@xxxxxx> --- drivers/usb/renesas_usbhs/fifo.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/usb/renesas_usbhs/fifo.c b/drivers/usb/renesas_usbhs/fifo.c index 47a6ffa..0c962ff 100644 --- a/drivers/usb/renesas_usbhs/fifo.c +++ b/drivers/usb/renesas_usbhs/fifo.c @@ -263,8 +263,17 @@ static void usbhsf_fifo_clear(struct usbhs_pipe *pipe, 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 -- 2.8.0.rc2.1.gbe9624a