usb: renesas_usbhs: Fix DMAC sequence for receiving zero-length packet
authorKazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com>
Mon, 2 Oct 2017 05:01:41 +0000 (14:01 +0900)
committerFelipe Balbi <felipe.balbi@linux.intel.com>
Wed, 11 Oct 2017 10:13:52 +0000 (13:13 +0300)
commit29c7f3e68eec4ae94d85ad7b5dfdafdb8089f513
tree68c543373d9b2030f37dd28d823446e5740a599c
parentab219221a5064abfff9f78c323c4a257b16cdb81
usb: renesas_usbhs: Fix DMAC sequence for receiving zero-length packet

The DREQE bit of the DnFIFOSEL should be set to 1 after the DE bit of
USB-DMAC on R-Car SoCs is set to 1 after the USB-DMAC received a
zero-length packet. Otherwise, a transfer completion interruption
of USB-DMAC doesn't happen. Even if the driver changes the sequence,
normal operations (transmit/receive without zero-length packet) will
not cause any side-effects. So, this patch fixes the sequence anyway.

Signed-off-by: Kazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com>
[shimoda: revise the commit log]
Fixes: e73a9891b3a1 ("usb: renesas_usbhs: add DMAEngine support")
Cc: <stable@vger.kernel.org> # v3.1+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
drivers/usb/renesas_usbhs/fifo.c