commit b1c5dbdde51f4b65a09af2e61f4048498ad05c7a
author Macpaul Lin <macpaul.lin@mediatek.com> Sun May 24 21:50:47 2020 -0500
committer Greg Kroah-Hartman <gregkh@google.com> Thu Jul 02 12:30:56 2020 +0000
tree 119ef8c23174b99c89b16543ce372355b2b7999e
parent 9fc96c1eb638997bc3e056110abae6b5478cbf4b

UPSTREAM: usb: musb: mediatek: add reset FADDR to zero in reset interrupt handle

When receiving reset interrupt, FADDR need to be reset to zero in
peripheral mode. Otherwise ep0 cannot do enumeration when re-plugging USB
cable.

Bug: 158724613
Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com>
Acked-by: Min Guo <min.guo@mediatek.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Link: https://lore.kernel.org/r/20200525025049.3400-5-b-liu@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 402bcac4b25b520c89ba60db85eb6316f36e797f)
Change-Id: I95ec2486aee1cd4db56f49138cbd781c099fa488

drivers/usb/musb/mediatek.c

diff --git a/drivers/usb/musb/mediatek.c b/drivers/usb/musb/mediatek.c
index 9fde80ed..eaf6bff 100644
--- a/drivers/usb/musb/mediatek.c
+++ b/drivers/usb/musb/mediatek.c
@@ -202,6 +202,12 @@
 	musb->int_rx = musb_clearw(musb->mregs, MUSB_INTRRX);
 	musb->int_tx = musb_clearw(musb->mregs, MUSB_INTRTX);
 
+	if ((musb->int_usb & MUSB_INTR_RESET) && !is_host_active(musb)) {
+		/* ep0 FADDR must be 0 when (re)entering peripheral mode */
+		musb_ep_select(musb->mregs, 0);
+		musb_writeb(musb->mregs, MUSB_FADDR, 0);
+	}
+
 	if (musb->int_usb || musb->int_tx || musb->int_rx)
 		retval = musb_interrupt(musb);