Re: [PATCH AUTOSEL 4.19 177/258] usb: musb: dsps: fix runtime pm for peripheral mode

[Bin Liu]

Hi Sasha,

On Mon, Jan 28, 2019 at 10:58:03AM -0500, Sasha Levin wrote:
> From: Bin Liu <b-liu@xxxxxx>
> 
> [ Upstream commit 54578ee883e34d2d1c518d48f1c1e2dd3f387188 ]
> 
> Since the runtime PM support was added in musb, dsps relies on the timer
> calling otg_timer() to activate the usb subsystem. However the driver
> doesn't enable the timer for peripheral port, then the peripheral port is
> unable to be enumerated by a host if the other usb port is disabled or in
> peripheral mode too.
> 
> So let's start the timer for peripheral port too.
> 
> Fixes: ea2f35c01d5e ("usb: musb: Fix sleeping function called from invalid context for hdrc glue")
> Acked-by: Tony Lindgren <tony@xxxxxxxxxxx>
> Signed-off-by: Bin Liu <b-liu@xxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
> ---
>  drivers/usb/musb/musb_dsps.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/musb/musb_dsps.c b/drivers/usb/musb/musb_dsps.c
> index 1e6d78b1334e..403eb97915f8 100644
> --- a/drivers/usb/musb/musb_dsps.c
> +++ b/drivers/usb/musb/musb_dsps.c
> @@ -181,9 +181,11 @@ static void dsps_musb_enable(struct musb *musb)
>  
>  	musb_writel(reg_base, wrp->epintr_set, epmask);
>  	musb_writel(reg_base, wrp->coreintr_set, coremask);
> -	/* start polling for ID change in dual-role idle mode */
> -	if (musb->xceiv->otg->state == OTG_STATE_B_IDLE &&
> -			musb->port_mode == MUSB_OTG)
> +	/*
> +	 * start polling for runtime PM active and idle,
> +	 * and for ID change in dual-role idle mode.
> +	 */
> +	if (musb->xceiv->otg->state == OTG_STATE_B_IDLE)
>  		dsps_mod_timer(glue, -1);
>  }
>  
> @@ -254,6 +256,10 @@ static int dsps_check_status(struct musb *musb, void *unused)
>  				musb->xceiv->otg->state = OTG_STATE_A_IDLE;
>  				MUSB_HST_MODE(musb);
>  			}
> +
> +			if (musb->port_mode == MUSB_PERIPHERAL)
> +				skip_session = 1;
> +
>  			if (!(devctl & MUSB_DEVCTL_SESSION) && !skip_session)
>  				musb_writeb(mregs, MUSB_DEVCTL,
>  					    MUSB_DEVCTL_SESSION);

This backport won't apply to stables cleanly. I have sent the manual
backport [1] for v4.9+ a few weeks ago.

[1] https://marc.info/?l=linux-usb&m=154696698103763&w=2

Regards,
-Bin.