Re: [PATCH v2] usb: typec: tcpci: pass correct rx_type to tcpm_pd_receive()

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

On Thu, Jul 23, 2026 at 06:46:14PM +0800, Xu Yang wrote:
> From: Xu Yang <xu.yang_2@nxp.com>
> 
> Previously, tcpci_irq() always passed TCPC_TX_SOP as the receive type
> to tcpm_pd_receive(), ignoring the actual frame type reported by the
> TCPC_RX_BUF_FRAME_TYPE register.
> 
> Cache the TCPC_RX_DETECT register value in rx_type_mask variable. When
> a PD messageis received, read TCPC_RX_BUF_FRAME_TYPE register and handle
> the message only if its frame type is enabled in mask.
> 
> The TCPC_RX_BUF_FRAME_TYPE register records the received message type,
> which has a 1:1 mapping to enum tcpm_transmit_type.
> 
> Fixes: fb7ff25ae433 ("usb: typec: tcpm: add discover identity support for SOP'")
> Cc: stable@vger.kernel.org
> Signed-off-by: Xu Yang <xu.yang_2@nxp.com>

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

> ---
> Changes in v2:
>  - add fix tag
>  - check return value when get RX SOP type
>  - pass all possible RX message type to tcpm_pd_receive()
>  - cache TCPC_RX_DETECT to filter out unallowed RX messages as suggested by Badhri
> ---
>  drivers/usb/typec/tcpm/tcpci.c | 12 +++++++++++-
>  include/linux/usb/tcpci.h      |  1 +
>  2 files changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
> index 7ac7000b2d13..6717ac914c6a 100644
> --- a/drivers/usb/typec/tcpm/tcpci.c
> +++ b/drivers/usb/typec/tcpm/tcpci.c
> @@ -38,6 +38,7 @@ struct tcpci {
>  
>  	struct regmap *regmap;
>  	unsigned int alert_mask;
> +	unsigned int rx_type_mask;
>  
>  	bool controls_vbus;
>  
> @@ -488,6 +489,8 @@ static int tcpci_set_pd_rx(struct tcpc_dev *tcpc, bool enable)
>  		if (tcpci->data->cable_comm_capable)
>  			reg |= TCPC_RX_DETECT_SOP1;
>  	}
> +
> +	tcpci->rx_type_mask = reg;
>  	ret = regmap_write(tcpci->regmap, TCPC_RX_DETECT, reg);
>  	if (ret < 0)
>  		return ret;
> @@ -749,6 +752,7 @@ irqreturn_t tcpci_irq(struct tcpci *tcpci)
>  	if (status & TCPC_ALERT_RX_STATUS) {
>  		struct pd_message msg;
>  		unsigned int cnt, payload_cnt;
> +		enum tcpm_transmit_type rx_type;
>  		u16 header;
>  
>  		regmap_read(tcpci->regmap, TCPC_RX_BYTE_CNT, &cnt);
> @@ -773,10 +777,16 @@ irqreturn_t tcpci_irq(struct tcpci *tcpci)
>  			regmap_raw_read(tcpci->regmap, TCPC_RX_DATA,
>  					&msg.payload, payload_cnt);
>  
> +		ret = regmap_read(tcpci->regmap, TCPC_RX_BUF_FRAME_TYPE, &rx_type);
> +		if (ret)
> +			return ret;
> +
>  		/* Read complete, clear RX status alert bit */
>  		tcpci_write16(tcpci, TCPC_ALERT, TCPC_ALERT_RX_STATUS);
>  
> -		tcpm_pd_receive(tcpci->port, &msg, TCPC_TX_SOP);
> +		rx_type &= TCPC_RX_BUF_FRAME_TYPE_MASK;
> +		if (tcpci->rx_type_mask & BIT(rx_type))
> +			tcpm_pd_receive(tcpci->port, &msg, rx_type);
>  	}
>  
>  	if (tcpci->data->vbus_vsafe0v && (status & TCPC_ALERT_EXTENDED_STATUS)) {
> diff --git a/include/linux/usb/tcpci.h b/include/linux/usb/tcpci.h
> index f7f5cfbdef12..9b46a6bc762c 100644
> --- a/include/linux/usb/tcpci.h
> +++ b/include/linux/usb/tcpci.h
> @@ -144,6 +144,7 @@
>  #define TCPC_RX_BUF_FRAME_TYPE		0x31
>  #define TCPC_RX_BUF_FRAME_TYPE_SOP	0
>  #define TCPC_RX_BUF_FRAME_TYPE_SOP1	1
> +#define TCPC_RX_BUF_FRAME_TYPE_MASK	GENMASK(2, 0)
>  #define TCPC_RX_HDR			0x32
>  #define TCPC_RX_DATA			0x34 /* through 0x4f */
>  
> -- 
> 2.34.1

-- 
heikki