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Subject: Re: [PATCH] phy: rockchip-inno-usb2: Return zero after otg sync
To:     Peter Geis <pgwipeout@gmail.com>, Heiko Stuebner <heiko@sntech.de>,
        Kishon Vijay Abraham I <kishon@ti.com>,
        Vinod Koul <vkoul@kernel.org>
Cc:     Markus Reichl <m.reichl@fivetechno.de>,
        Michael Riesch <michael.riesch@wolfvision.net>,
        linux-phy@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org,
        linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org
References: <20220822103219.3985075-1-pgwipeout@gmail.com>
From:   Samuel Holland <samuel@sholland.org>
Message-ID: <717fe4e0-ef9c-edef-80d1-caeeae1319b9@sholland.org>
Date:   Mon, 22 Aug 2022 22:41:27 -0500
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On 8/22/22 5:32 AM, Peter Geis wrote:
> The otg sync state patch reuses the ret variable, but fails to set it to
> zero after use. This leads to a situation when the otg port is in
> peripheral mode where the otg phy aborts halfway through setup. Fix this
> by setting ret to zero after use.
> 
> Fixes: 8dc60f8da22f ("phy: rockchip-inno-usb2: Sync initial otg state")
> 
> Reported-by: Markus Reichl <m.reichl@fivetechno.de>
> Reported-by: Michael Riesch <michael.riesch@wolfvision.net>
> Signed-off-by: Peter Geis <pgwipeout@gmail.com>
> Tested-by: Michael Riesch <michael.riesch@wolfvision.net>
> Tested-by: Markus Reichl <m.reichl@fivetechno.de>
> ---
>  drivers/phy/rockchip/phy-rockchip-inno-usb2.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/phy/rockchip/phy-rockchip-inno-usb2.c b/drivers/phy/rockchip/phy-rockchip-inno-usb2.c
> index 0b1e9337ee8e..5fc7c374a6b4 100644
> --- a/drivers/phy/rockchip/phy-rockchip-inno-usb2.c
> +++ b/drivers/phy/rockchip/phy-rockchip-inno-usb2.c
> @@ -1169,6 +1169,7 @@ static int rockchip_usb2phy_otg_port_init(struct rockchip_usb2phy *rphy,
>  			/* do initial sync of usb state */
>  			ret = property_enabled(rphy->grf, &rport->port_cfg->utmi_id);
>  			extcon_set_state_sync(rphy->edev, EXTCON_USB_HOST, !ret);
> +			ret = 0;

The bug was caused by the unexpected consequence of (mis|re)using the "ret"
variable for a temporary value. Please introduce a new variable here, else the
use of "ret" is even more confusing. This code also wipes out any error returned
by devm_extcon_register_notifier().

Regards,
Samuel