linux-kernel - Re: [PATCH v2] usb: typec: mux: intel: Handle alt mode HPD

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Message-ID: <20200429123203.GB2738754@kuha.fi.intel.com>
Date:   Wed, 29 Apr 2020 15:32:03 +0300
From:   Heikki Krogerus <heikki.krogerus@...ux.intel.com>
To:     Prashant Malani <pmalani@...omium.org>
Cc:     linux-kernel@...r.kernel.org, bleung@...omium.org,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "open list:USB TYPEC CLASS" <linux-usb@...r.kernel.org>
Subject: Re: [PATCH v2] usb: typec: mux: intel: Handle alt mode HPD_HIGH

On Tue, Apr 28, 2020 at 10:44:28PM -0700, Prashant Malani wrote:
> According to the PMC Type C Subsystem (TCSS) Mux programming guide rev
> 0.6, when a device is transitioning to DP Alternate Mode state, if the
> HPD_STATE (bit 7) field in the status update command VDO is set to
> HPD_HIGH, the HPD_HIGH field in the Alternate Mode request “mode_data”
> field (bit 14) should also be set. Ensure the bit is correctly handled
> while issuing the Alternate Mode request.
> 
> Signed-off-by: Prashant Malani <pmalani@...omium.org>
> Fixes: 6701adfa9693 ("usb: typec: driver for Intel PMC mux control")

Acked-by: Heikki Krogerus <heikki.krogerus@...ux.intel.com>

> ---
> 
> Changes in v2:
> - Clarified the commit message to mention the proper field names.
> 
>  drivers/usb/typec/mux/intel_pmc_mux.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/usb/typec/mux/intel_pmc_mux.c b/drivers/usb/typec/mux/intel_pmc_mux.c
> index f5c5e0aef66f..c599112559e7 100644
> --- a/drivers/usb/typec/mux/intel_pmc_mux.c
> +++ b/drivers/usb/typec/mux/intel_pmc_mux.c
> @@ -157,6 +157,10 @@ pmc_usb_mux_dp(struct pmc_usb_port *port, struct typec_mux_state *state)
>  	req.mode_data |= (state->mode - TYPEC_STATE_MODAL) <<
>  			 PMC_USB_ALTMODE_DP_MODE_SHIFT;
>  
> +	if (data->status & DP_STATUS_HPD_STATE)
> +		req.mode_data |= PMC_USB_DP_HPD_LVL <<
> +				 PMC_USB_ALTMODE_DP_MODE_SHIFT;
> +
>  	return pmc_usb_command(port, (void *)&req, sizeof(req));
>  }
>  
> -- 
> 2.26.2.303.gf8c07b1a785-goog

thanks,

-- 
heikki