2023-05-05 17:24:48

by Christophe JAILLET

[permalink] [raw]
Subject: [PATCH] usb: dwc2: Fix some error handling paths

dwc2_driver_probe() calls dwc2_lowlevel_hw_init() which deassert some reset
lines.
Should an error happen in dwc2_lowlevel_hw_init() after calling
reset_control_deassert() or in the probe after calling
dwc2_lowlevel_hw_init(), the reset lines remain deasserted.

Add some devm_add_action_or_reset() calls to re-assert the lines if needed.

Update the remove function accordingly.

This change is compile-tested only.

Fixes: 83f8da562f8b ("usb: dwc2: Add reset control to dwc2")
Signed-off-by: Christophe JAILLET <[email protected]>
---
drivers/usb/dwc2/platform.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 5aee284018c0..5cf025511cce 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -203,6 +203,11 @@ int dwc2_lowlevel_hw_disable(struct dwc2_hsotg *hsotg)
return ret;
}

+static void dwc2_reset_control_assert(void *data)
+{
+ reset_control_assert(data);
+}
+
static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
{
int i, ret;
@@ -213,6 +218,10 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
"error getting reset control\n");

reset_control_deassert(hsotg->reset);
+ ret = devm_add_action_or_reset(hsotg->dev, dwc2_reset_control_assert,
+ hsotg->reset);
+ if (ret)
+ return ret;

hsotg->reset_ecc = devm_reset_control_get_optional(hsotg->dev, "dwc2-ecc");
if (IS_ERR(hsotg->reset_ecc))
@@ -220,6 +229,10 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
"error getting reset control for ecc\n");

reset_control_deassert(hsotg->reset_ecc);
+ ret = devm_add_action_or_reset(hsotg->dev, dwc2_reset_control_assert,
+ hsotg->reset_ecc);
+ if (ret)
+ return ret;

/*
* Attempt to find a generic PHY, then look for an old style
@@ -339,9 +352,6 @@ static int dwc2_driver_remove(struct platform_device *dev)
if (hsotg->ll_hw_enabled)
dwc2_lowlevel_hw_disable(hsotg);

- reset_control_assert(hsotg->reset);
- reset_control_assert(hsotg->reset_ecc);
-
return 0;
}

--
2.34.1


2023-05-16 05:51:27

by Minas Harutyunyan

[permalink] [raw]
Subject: Re: [PATCH] usb: dwc2: Fix some error handling paths



On 5/5/23 21:15, Christophe JAILLET wrote:
> dwc2_driver_probe() calls dwc2_lowlevel_hw_init() which deassert some reset
> lines.
> Should an error happen in dwc2_lowlevel_hw_init() after calling
> reset_control_deassert() or in the probe after calling
> dwc2_lowlevel_hw_init(), the reset lines remain deasserted.
>
> Add some devm_add_action_or_reset() calls to re-assert the lines if needed.
>
> Update the remove function accordingly.
>
> This change is compile-tested only.
>
> Fixes: 83f8da562f8b ("usb: dwc2: Add reset control to dwc2")
> Signed-off-by: Christophe JAILLET <[email protected]>

Acked-by: Minas Harutyunyan <[email protected]>

> ---
> drivers/usb/dwc2/platform.c | 16 +++++++++++++---
> 1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
> index 5aee284018c0..5cf025511cce 100644
> --- a/drivers/usb/dwc2/platform.c
> +++ b/drivers/usb/dwc2/platform.c
> @@ -203,6 +203,11 @@ int dwc2_lowlevel_hw_disable(struct dwc2_hsotg *hsotg)
> return ret;
> }
>
> +static void dwc2_reset_control_assert(void *data)
> +{
> + reset_control_assert(data);
> +}
> +
> static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
> {
> int i, ret;
> @@ -213,6 +218,10 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
> "error getting reset control\n");
>
> reset_control_deassert(hsotg->reset);
> + ret = devm_add_action_or_reset(hsotg->dev, dwc2_reset_control_assert,
> + hsotg->reset);
> + if (ret)
> + return ret;
>
> hsotg->reset_ecc = devm_reset_control_get_optional(hsotg->dev, "dwc2-ecc");
> if (IS_ERR(hsotg->reset_ecc))
> @@ -220,6 +229,10 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
> "error getting reset control for ecc\n");
>
> reset_control_deassert(hsotg->reset_ecc);
> + ret = devm_add_action_or_reset(hsotg->dev, dwc2_reset_control_assert,
> + hsotg->reset_ecc);
> + if (ret)
> + return ret;
>
> /*
> * Attempt to find a generic PHY, then look for an old style
> @@ -339,9 +352,6 @@ static int dwc2_driver_remove(struct platform_device *dev)
> if (hsotg->ll_hw_enabled)
> dwc2_lowlevel_hw_disable(hsotg);
>
> - reset_control_assert(hsotg->reset);
> - reset_control_assert(hsotg->reset_ecc);
> -
> return 0;
> }
>