Re: [PATCH] phy: exynos5-usbdrd: fix HS phy init count imbalance on Exynos2200

[Ivaylo Ivanov <ivo.ivanov.ivanov1@gmail.com>]

On 11/10/26 02:15, Soheyb wrote:
> exynos2200_usbdrd_utmi_init() calls phy_init() on the high-speed phy,
> but exynos2200_usbdrd_phy_exit() never calls phy_exit() on it. The init
> count of the high-speed phy therefore never drops back to zero: after
> the first init, every later phy_init() of it returns early, and its
> clocks and supplies stay enabled across an exit of the UTMI phy.
>
> When the high-speed phy loses power while the controller is suspended,
> it is thus not set up again on resume, and the DWC3 core soft reset
> times out:
>
>    dwc3 11210000.usb: DWC3 controller soft reset failed
>
> Exit the high-speed phy when the UTMI phy exits, first, in the reverse
> order of the init.
>
> Fixes: cc52a697f87e ("phy: exynos5-usbdrd: support Exynos USBDRD 3.2 4nm controller")
> Cc: stable@vger.kernel.org
> Signed-off-by: Soheyb <soheyb_boulaa@proton.me>
> ---
> Tested on a Google Pixel 9 (Tensor G4) with an out-of-tree port that
> uses the Exynos2200 phy ops and powers the USB block off in system
> sleep: without this change the soft reset failed on the first resume;
> with it, USB came back after each of two system sleeps. Not tested on
> Exynos2200 hardware.
>
>   drivers/phy/samsung/phy-exynos5-usbdrd.c | 7 +++++++
>   1 file changed, 7 insertions(+)
>
> diff --git a/drivers/phy/samsung/phy-exynos5-usbdrd.c b/drivers/phy/samsung/phy-exynos5-usbdrd.c
> index 087d552..0bee928 100644
> --- a/drivers/phy/samsung/phy-exynos5-usbdrd.c
> +++ b/drivers/phy/samsung/phy-exynos5-usbdrd.c
> @@ -1486,6 +1486,13 @@ static int exynos2200_usbdrd_phy_exit(struct phy *phy)
>   	u32 reg;
>   	int ret;
>   
> +	/*
> +	 * The UTMI init initializes the high-speed phy; exit it in turn, so
> +	 * that the next init sets it up again after it lost power.
> +	 */

I think the function is pretty self-explanatory, so could drop the
comment. Otherwise looks good to me, nice catch!

Acked-by: Ivaylo Ivanov <ivo.ivanov.ivanov1@gmail.com>

Best regards,
Ivaylo

> +	if (inst->phy_cfg->id == EXYNOS5_DRDPHY_UTMI)
> +		phy_exit(phy_drd->hs_phy);
> +
>   	ret = clk_bulk_prepare_enable(phy_drd->drv_data->n_clks, phy_drd->clks);
>   	if (ret)
>   		return ret;