From: Macpaul Lin <macpaul.lin@xxxxxxxxxxxx> 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@xxxxxxxxxxxx> Acked-by: Min Guo <min.guo@xxxxxxxxxxxx> Signed-off-by: Bin Liu <b-liu@xxxxxx> Link: https://lore.kernel.org/r/20200525025049.3400-5-b-liu@xxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/musb/mediatek.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/usb/musb/mediatek.c +++ b/drivers/usb/musb/mediatek.c @@ -208,6 +208,12 @@ static irqreturn_t generic_interrupt(int 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);
