Re: [PATCH] usb: ehci-hcd: fix call balance of clocks handling routines

[Fedor Pchelkin]

On Thu, 21. Nov 14:47, Vitalii Mordan wrote:
> If the clocks priv->iclk and priv->fclk were not enabled in ehci_hcd_sh_probe,
> they should not be disabled in any path.
> 
> Conversely, if they was enabled in ehci_hcd_sh_probe, they must be disabled
> in all error paths to ensure proper cleanup.
> 
> Found by Linux Verification Center (linuxtesting.org) with Klever.
> 
> Fixes: 63c845522263 ("usb: ehci-hcd: Add support for SuperH EHCI.")
> Cc: stable@xxxxxxxxxxxxxxx # ff30bd6a6618: sh: clk: Fix clk_enable() to return 0 on NULL clk
> Signed-off-by: Vitalii Mordan <mordan@xxxxxxxxx>
> ---

The current patch was added to stable kernels lacking the necessary
prerequisite ff30bd6a6618 ("sh: clk: Fix clk_enable() to return 0 on
NULL clk") which is specified in Cc:stable tag of the commit description
per stable kernels documentation [1].

[1]: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html#option-1

Could you please cherry-pick ff30bd6a6618 ("sh: clk: Fix clk_enable() to
return 0 on NULL clk") to 6.1.y, 5.15.y, 5.10.y and 5.4.y ? It applies
cleanly.

Thanks!

>  drivers/usb/host/ehci-sh.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/host/ehci-sh.c b/drivers/usb/host/ehci-sh.c
> index d31d9506e41a..77460aac6dbd 100644
> --- a/drivers/usb/host/ehci-sh.c
> +++ b/drivers/usb/host/ehci-sh.c
> @@ -119,8 +119,12 @@ static int ehci_hcd_sh_probe(struct platform_device *pdev)
>  	if (IS_ERR(priv->iclk))
>  		priv->iclk = NULL;
>  
> -	clk_enable(priv->fclk);
> -	clk_enable(priv->iclk);
> +	ret = clk_enable(priv->fclk);
> +	if (ret)
> +		goto fail_request_resource;
> +	ret = clk_enable(priv->iclk);
> +	if (ret)
> +		goto fail_iclk;
>  
>  	ret = usb_add_hcd(hcd, irq, IRQF_SHARED);
>  	if (ret != 0) {
> @@ -136,6 +140,7 @@ static int ehci_hcd_sh_probe(struct platform_device *pdev)
>  
>  fail_add_hcd:
>  	clk_disable(priv->iclk);
> +fail_iclk:
>  	clk_disable(priv->fclk);
>  
>  fail_request_resource:
> -- 
> 2.25.1
>