[PATCH 1/1] usb: dwc3: meson-g12a: fix shared reset control use

[Neil Armstrong]

Hi,

Le 13/07/2020 à 18:05, Dan Robertson a écrit :
> The reset is a shared reset line, but reset_control_reset is still used
> and reset_control_deassert is not guaranteed to have been called before
> the first reset_control_assert call. When suspending the following
> warning may be seen:
> 
> WARNING: CPU: 1 PID: 5530 at drivers/reset/core.c:355 reset_control_assert+0x184/0x19c
> Hardware name: Hardkernel ODROID-N2 (DT)
> [..]
> pc : reset_control_assert+0x184/0x19c
> lr : dwc3_meson_g12a_suspend+0x68/0x7c
> [..]
> Call trace:
>  reset_control_assert+0x184/0x19c
>  dwc3_meson_g12a_suspend+0x68/0x7c
>  platform_pm_suspend+0x28/0x54
>  __device_suspend+0x590/0xabc
>  dpm_suspend+0x104/0x404
>  dpm_suspend_start+0x84/0x1bc
>  suspend_devices_and_enter+0xc4/0x4fc
>  pm_suspend+0x198/0x2d4
> 
> Fixes: 6d9fa35a347a87 ("usb: dwc3: meson-g12a: get the reset as shared")
> Signed-off-by: Dan Robertson <dan at dlrobertson.com>
> ---
>  drivers/usb/dwc3/dwc3-meson-g12a.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-meson-g12a.c b/drivers/usb/dwc3/dwc3-meson-g12a.c
> index 1f7f4d88ed9d..88b75b5a039c 100644
> --- a/drivers/usb/dwc3/dwc3-meson-g12a.c
> +++ b/drivers/usb/dwc3/dwc3-meson-g12a.c
> @@ -737,13 +737,13 @@ static int dwc3_meson_g12a_probe(struct platform_device *pdev)
>  		goto err_disable_clks;
>  	}
>  
> -	ret = reset_control_reset(priv->reset);
> +	ret = reset_control_deassert(priv->reset);
>  	if (ret)
> -		goto err_disable_clks;
> +		goto err_assert_reset;
>  
>  	ret = dwc3_meson_g12a_get_phys(priv);
>  	if (ret)
> -		goto err_disable_clks;
> +		goto err_assert_reset;
>  
>  	ret = priv->drvdata->setup_regmaps(priv, base);
>  	if (ret)
> @@ -752,7 +752,7 @@ static int dwc3_meson_g12a_probe(struct platform_device *pdev)
>  	if (priv->vbus) {
>  		ret = regulator_enable(priv->vbus);
>  		if (ret)
> -			goto err_disable_clks;
> +			goto err_assert_reset;
>  	}
>  
>  	/* Get dr_mode */
> @@ -765,13 +765,13 @@ static int dwc3_meson_g12a_probe(struct platform_device *pdev)
>  
>  	ret = priv->drvdata->usb_init(priv);
>  	if (ret)
> -		goto err_disable_clks;
> +		goto err_assert_reset;
>  
>  	/* Init PHYs */
>  	for (i = 0 ; i < PHY_COUNT ; ++i) {
>  		ret = phy_init(priv->phys[i]);
>  		if (ret)
> -			goto err_disable_clks;
> +			goto err_assert_reset;
>  	}
>  
>  	/* Set PHY Power */
> @@ -809,6 +809,9 @@ static int dwc3_meson_g12a_probe(struct platform_device *pdev)
>  	for (i = 0 ; i < PHY_COUNT ; ++i)
>  		phy_exit(priv->phys[i]);
>  
> +err_assert_reset:
> +	reset_control_assert(priv->reset);
> +
>  err_disable_clks:
>  	clk_bulk_disable_unprepare(priv->drvdata->num_clks,
>  				   priv->drvdata->clks);
> 


This should do the trick, I'll need to check first if it doesn't break the GXL/GXM
support first.

thanks for the fix

Neil