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

commit 402bcac4b25b520c89ba60db85eb6316f36e797f upstream.

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

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>

diff --git a/drivers/usb/musb/mediatek.c b/drivers/usb/musb/mediatek.c
index 6196b0e8d77d2016d6746be91f289134da37f5b4..eebeadd269461421b7e6915adc1a106c249112d2 100644 (file)
--- a/drivers/usb/musb/mediatek.c
+++ b/drivers/usb/musb/mediatek.c
@@ -208,6 +208,12 @@ static irqreturn_t generic_interrupt(int irq, void *__hci)
        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);