Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 07/47] usb: renesas_usbhs: fix usbhsf_fifo_clear() for RX direction | Date | Tue, 10 Oct 2017 21:50:20 +0200 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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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 @@ -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
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