[PATCH] Revert "usb: dwc3: meson-g12a: fix shared reset control use"

[PATCH] Revert "usb: dwc3: meson-g12a: fix shared reset control use"

[Amjad Ouled-Ameur]

This reverts commit 7a410953d1fb4dbe91ffcfdee9cbbf889d19b0d7.

This commit breaks USB on meson-gxl-s905x-libretech-cc. Reverting
the change solves the issue.

In fact, according to the reset framework code, consumers must not use
reset_control_(de)assert() on shared reset lines when reset_control_reset
has been used, and vice-versa.

Moreover, with this commit, usb is not guaranted to be reset since the
reset is likely to be initially deasserted.

Reverting the commit will bring back the suspend warning mentioned in the
commit description. Nevertheless, a warning is much less critical than
breaking dwc3-meson-g12a USB completely. We will address the warning
issue in another way as a 2nd step.

Signed-off-by: Amjad Ouled-Ameur <aouledameur@baylibre.com>
Reported-by: Jerome Brunet <jbrunet@baylibre.com>
---
 drivers/usb/dwc3/dwc3-meson-g12a.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-meson-g12a.c b/drivers/usb/dwc3/dwc3-meson-g12a.c
index 88b75b5a039c..1f7f4d88ed9d 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_deassert(priv->reset);
+	ret = reset_control_reset(priv->reset);
 	if (ret)
-		goto err_assert_reset;
+		goto err_disable_clks;
 
 	ret = dwc3_meson_g12a_get_phys(priv);
 	if (ret)
-		goto err_assert_reset;
+		goto err_disable_clks;
 
 	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_assert_reset;
+			goto err_disable_clks;
 	}
 
 	/* 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_assert_reset;
+		goto err_disable_clks;
 
 	/* Init PHYs */
 	for (i = 0 ; i < PHY_COUNT ; ++i) {
 		ret = phy_init(priv->phys[i]);
 		if (ret)
-			goto err_assert_reset;
+			goto err_disable_clks;
 	}
 
 	/* Set PHY Power */
@@ -809,9 +809,6 @@ 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);
-- 
2.17.1

Re: [PATCH] Revert "usb: dwc3: meson-g12a: fix shared reset control use"

[Neil Armstrong]

On 27/08/2020 16:48, Amjad Ouled-Ameur wrote:
> This reverts commit 7a410953d1fb4dbe91ffcfdee9cbbf889d19b0d7.
> 
> This commit breaks USB on meson-gxl-s905x-libretech-cc. Reverting
> the change solves the issue.
> 
> In fact, according to the reset framework code, consumers must not use
> reset_control_(de)assert() on shared reset lines when reset_control_reset
> has been used, and vice-versa.
> 
> Moreover, with this commit, usb is not guaranted to be reset since the
> reset is likely to be initially deasserted.
> 
> Reverting the commit will bring back the suspend warning mentioned in the
> commit description. Nevertheless, a warning is much less critical than
> breaking dwc3-meson-g12a USB completely. We will address the warning
> issue in another way as a 2nd step.
> 
> Signed-off-by: Amjad Ouled-Ameur <aouledameur@baylibre.com>
> Reported-by: Jerome Brunet <jbrunet@baylibre.com>
> ---
>  drivers/usb/dwc3/dwc3-meson-g12a.c | 15 ++++++---------
>  1 file changed, 6 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-meson-g12a.c b/drivers/usb/dwc3/dwc3-meson-g12a.c
> index 88b75b5a039c..1f7f4d88ed9d 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_deassert(priv->reset);
> +	ret = reset_control_reset(priv->reset);
>  	if (ret)
> -		goto err_assert_reset;
> +		goto err_disable_clks;
>  
>  	ret = dwc3_meson_g12a_get_phys(priv);
>  	if (ret)
> -		goto err_assert_reset;
> +		goto err_disable_clks;
>  
>  	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_assert_reset;
> +			goto err_disable_clks;
>  	}
>  
>  	/* 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_assert_reset;
> +		goto err_disable_clks;
>  
>  	/* Init PHYs */
>  	for (i = 0 ; i < PHY_COUNT ; ++i) {
>  		ret = phy_init(priv->phys[i]);
>  		if (ret)
> -			goto err_assert_reset;
> +			goto err_disable_clks;
>  	}
>  
>  	/* Set PHY Power */
> @@ -809,9 +809,6 @@ 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);
> 

Acked-by: Neil Armstrong <narmstrong@baylibre.com>

Re: [PATCH] Revert "usb: dwc3: meson-g12a: fix shared reset control use"

[Philipp Zabel]

On Thu, 2020-08-27 at 16:48 +0200, Amjad Ouled-Ameur wrote:
> This reverts commit 7a410953d1fb4dbe91ffcfdee9cbbf889d19b0d7.
> 
> This commit breaks USB on meson-gxl-s905x-libretech-cc. Reverting
> the change solves the issue.
> 
> In fact, according to the reset framework code, consumers must not use
> reset_control_(de)assert() on shared reset lines when reset_control_reset
> has been used, and vice-versa.
> 
> Moreover, with this commit, usb is not guaranted to be reset since the
> reset is likely to be initially deasserted.
> 
> Reverting the commit will bring back the suspend warning mentioned in the
> commit description. Nevertheless, a warning is much less critical than
> breaking dwc3-meson-g12a USB completely. We will address the warning
> issue in another way as a 2nd step.
> 
> Signed-off-by: Amjad Ouled-Ameur <aouledameur@baylibre.com>
> Reported-by: Jerome Brunet <jbrunet@baylibre.com>

Acked-by: Philipp Zabel <p.zabel@pengutronix.de>

regards
Philipp

Re: [PATCH] Revert "usb: dwc3: meson-g12a: fix shared reset control use"

[Neil Armstrong]

Hi Felipe, Greg,

Is it possible to apply this ? USB is broken on 5.8 stable and 5.9-rc on multiple GXL/GXM boards.

Thanks,
Neil

On 27/08/2020 16:48, Amjad Ouled-Ameur wrote:
> This reverts commit 7a410953d1fb4dbe91ffcfdee9cbbf889d19b0d7.
> 
> This commit breaks USB on meson-gxl-s905x-libretech-cc. Reverting
> the change solves the issue.
> 
> In fact, according to the reset framework code, consumers must not use
> reset_control_(de)assert() on shared reset lines when reset_control_reset
> has been used, and vice-versa.
> 
> Moreover, with this commit, usb is not guaranted to be reset since the
> reset is likely to be initially deasserted.
> 
> Reverting the commit will bring back the suspend warning mentioned in the
> commit description. Nevertheless, a warning is much less critical than
> breaking dwc3-meson-g12a USB completely. We will address the warning
> issue in another way as a 2nd step.
> 
> Signed-off-by: Amjad Ouled-Ameur <aouledameur@baylibre.com>
> Reported-by: Jerome Brunet <jbrunet@baylibre.com>
> ---
>  drivers/usb/dwc3/dwc3-meson-g12a.c | 15 ++++++---------
>  1 file changed, 6 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-meson-g12a.c b/drivers/usb/dwc3/dwc3-meson-g12a.c
> index 88b75b5a039c..1f7f4d88ed9d 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_deassert(priv->reset);
> +	ret = reset_control_reset(priv->reset);
>  	if (ret)
> -		goto err_assert_reset;
> +		goto err_disable_clks;
>  
>  	ret = dwc3_meson_g12a_get_phys(priv);
>  	if (ret)
> -		goto err_assert_reset;
> +		goto err_disable_clks;
>  
>  	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_assert_reset;
> +			goto err_disable_clks;
>  	}
>  
>  	/* 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_assert_reset;
> +		goto err_disable_clks;
>  
>  	/* Init PHYs */
>  	for (i = 0 ; i < PHY_COUNT ; ++i) {
>  		ret = phy_init(priv->phys[i]);
>  		if (ret)
> -			goto err_assert_reset;
> +			goto err_disable_clks;
>  	}
>  
>  	/* Set PHY Power */
> @@ -809,9 +809,6 @@ 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);
> 

Re: [PATCH] Revert "usb: dwc3: meson-g12a: fix shared reset control use"

[Greg Kroah-Hartman]

On Wed, Sep 02, 2020 at 08:57:42AM +0200, Neil Armstrong wrote:
> Hi Felipe, Greg,
> 
> Is it possible to apply this ? USB is broken on 5.8 stable and 5.9-rc on multiple GXL/GXM boards.

Yes, will queue it up now, thanks.

greg k-h