[PATCH] phy: rockchip-typec: fix tcphy_get_mode error case

[PATCH] phy: rockchip-typec: fix tcphy_get_mode error case

[Neill Kapron]

The existing logic in tcphy_get_mode() can cause the phy to be
incorrectly configured to USB UFP or DisplayPort mode when
extcon_get_state returns an error code.

extcon_get_state() can return 0, 1, or a negative error code.

It is possible to get into the failing state with an extcon driver
which does not support the extcon connector id specified as the
second argument to extcon_get_state().

tcphy_get_mode()
->extcon_get_state()
-->find_cable_index_by_id()
--->return -EINVAL;

Fixes: e96be45cb84e ("phy: Add USB Type-C PHY driver for rk3399")
Signed-off-by: Neill Kapron <nkapron@google.com>
---
 drivers/phy/rockchip/phy-rockchip-typec.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/phy/rockchip/phy-rockchip-typec.c b/drivers/phy/rockchip/phy-rockchip-typec.c
index d76440ae10ff..6aea512e5d4e 100644
--- a/drivers/phy/rockchip/phy-rockchip-typec.c
+++ b/drivers/phy/rockchip/phy-rockchip-typec.c
@@ -821,10 +821,10 @@ static int tcphy_get_mode(struct rockchip_typec_phy *tcphy)
 	mode = MODE_DFP_USB;
 	id = EXTCON_USB_HOST;
 
-	if (ufp) {
+	if (ufp > 0) {
 		mode = MODE_UFP_USB;
 		id = EXTCON_USB;
-	} else if (dp) {
+	} else if (dp > 0) {
 		mode = MODE_DFP_DP;
 		id = EXTCON_DISP_DP;
 
-- 
2.39.1.456.gfc5497dd1b-goog

Re: [PATCH] phy: rockchip-typec: fix tcphy_get_mode error case

[Lee Jones]

On Thu, 26 Jan 2023, Neill Kapron wrote:

> The existing logic in tcphy_get_mode() can cause the phy to be
> incorrectly configured to USB UFP or DisplayPort mode when
> extcon_get_state returns an error code.
> 
> extcon_get_state() can return 0, 1, or a negative error code.
> 
> It is possible to get into the failing state with an extcon driver
> which does not support the extcon connector id specified as the
> second argument to extcon_get_state().
> 
> tcphy_get_mode()
> ->extcon_get_state()
> -->find_cable_index_by_id()
> --->return -EINVAL;
> 
> Fixes: e96be45cb84e ("phy: Add USB Type-C PHY driver for rk3399")
> Signed-off-by: Neill Kapron <nkapron@google.com>
> ---
>  drivers/phy/rockchip/phy-rockchip-typec.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Good catch.

Reviewed-by: Lee Jones <lee@kernel.org>

> diff --git a/drivers/phy/rockchip/phy-rockchip-typec.c b/drivers/phy/rockchip/phy-rockchip-typec.c
> index d76440ae10ff..6aea512e5d4e 100644
> --- a/drivers/phy/rockchip/phy-rockchip-typec.c
> +++ b/drivers/phy/rockchip/phy-rockchip-typec.c
> @@ -821,10 +821,10 @@ static int tcphy_get_mode(struct rockchip_typec_phy *tcphy)
>  	mode = MODE_DFP_USB;
>  	id = EXTCON_USB_HOST;
>  
> -	if (ufp) {
> +	if (ufp > 0) {
>  		mode = MODE_UFP_USB;
>  		id = EXTCON_USB;
> -	} else if (dp) {
> +	} else if (dp > 0) {
>  		mode = MODE_DFP_DP;
>  		id = EXTCON_DISP_DP;
>  
> -- 
> 2.39.1.456.gfc5497dd1b-goog

-- 
Lee Jones [李琼斯]

Re: [PATCH] phy: rockchip-typec: fix tcphy_get_mode error case

[Vinod Koul]

On 26-01-23, 00:10, Neill Kapron wrote:
> The existing logic in tcphy_get_mode() can cause the phy to be
> incorrectly configured to USB UFP or DisplayPort mode when
> extcon_get_state returns an error code.
> 
> extcon_get_state() can return 0, 1, or a negative error code.
> 
> It is possible to get into the failing state with an extcon driver
> which does not support the extcon connector id specified as the
> second argument to extcon_get_state().
> 
> tcphy_get_mode()
> ->extcon_get_state()
> -->find_cable_index_by_id()
> --->return -EINVAL;

Applied, thanks

-- 
~Vinod