Re: [PATCH] usb: typec: mux: intel_pmc_mux: Fix DP alternate mode entry

[Prashant Malani <pmalani@chromium.org>]

Hi Heikki,

On Fri, May 29, 2020 at 04:17:53PM +0300, Heikki Krogerus wrote:
> The PMC needs to be notified separately about HPD (hotplug
> detected) signal being high after mode entry. There is a bit
> "HPD High" in the Alternate Mode Request that the driver
> already sets, but that bit is only valid when the
> DisplayPort Alternate Mode is directly entered from
> disconnected state.
> 
> Fixes: 5c4edcdbcd97 ("usb: typec: mux: intel: Fix DP_HPD_LVL bit field")
> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

Tried this out; my DP monitor seems to enumerate correctly, so:

Tested-by: Prashant Malani <pmalani@chromium.org>
> ---
>  drivers/usb/typec/mux/intel_pmc_mux.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/typec/mux/intel_pmc_mux.c b/drivers/usb/typec/mux/intel_pmc_mux.c
> index 962bc69a6a59e..70ddc9d6d49e4 100644
> --- a/drivers/usb/typec/mux/intel_pmc_mux.c
> +++ b/drivers/usb/typec/mux/intel_pmc_mux.c
> @@ -148,7 +148,8 @@ pmc_usb_mux_dp_hpd(struct pmc_usb_port *port, struct typec_mux_state *state)
>  	msg[0] = PMC_USB_DP_HPD;
>  	msg[0] |= port->usb3_port << PMC_USB_MSG_USB3_PORT_SHIFT;
>  
> -	msg[1] = PMC_USB_DP_HPD_IRQ;
> +	if (data->status & DP_STATUS_IRQ_HPD)
> +		msg[1] = PMC_USB_DP_HPD_IRQ;
>  
>  	if (data->status & DP_STATUS_HPD_STATE)
>  		msg[1] |= PMC_USB_DP_HPD_LVL;
> @@ -161,6 +162,7 @@ pmc_usb_mux_dp(struct pmc_usb_port *port, struct typec_mux_state *state)
>  {
>  	struct typec_displayport_data *data = state->data;
>  	struct altmode_req req = { };
> +	int ret;
>  
>  	if (data->status & DP_STATUS_IRQ_HPD)
>  		return pmc_usb_mux_dp_hpd(port, state);
> @@ -181,7 +183,14 @@ pmc_usb_mux_dp(struct pmc_usb_port *port, struct typec_mux_state *state)
>  	if (data->status & DP_STATUS_HPD_STATE)
>  		req.mode_data |= PMC_USB_ALTMODE_HPD_HIGH;
>  
> -	return pmc_usb_command(port, (void *)&req, sizeof(req));
> +	ret = pmc_usb_command(port, (void *)&req, sizeof(req));
> +	if (ret)
> +		return ret;
> +
> +	if (data->status & DP_STATUS_HPD_STATE)
> +		return pmc_usb_mux_dp_hpd(port, state);
> +
> +	return 0;
>  }
>  
>  static int
> -- 
> 2.26.2
>