Re: [PATCH] usb: host: ehci-msm: Conditionally call ehci suspend/resume

[Alan Stern]

On Fri, 20 May 2016, Andy Gross wrote:

> This patch fixes a suspend/resume issue where the driver is blindly
> calling ehci_suspend/resume functions when the ehci hasn't been setup.
> This results in a crash during suspend/resume operations.
> 
> Signed-off-by: Andy Gross <andy.gross@xxxxxxxxxx>
> ---
>  drivers/usb/host/ehci-msm.c | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/host/ehci-msm.c b/drivers/usb/host/ehci-msm.c
> index 3e226ef..9996a60 100644
> --- a/drivers/usb/host/ehci-msm.c
> +++ b/drivers/usb/host/ehci-msm.c
> @@ -179,22 +179,32 @@ static int ehci_msm_remove(struct platform_device *pdev)
>  static int ehci_msm_pm_suspend(struct device *dev)
>  {
>  	struct usb_hcd *hcd = dev_get_drvdata(dev);
> +	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
>  	bool do_wakeup = device_may_wakeup(dev);
>  
>  	dev_dbg(dev, "ehci-msm PM suspend\n");
>  
> -	return ehci_suspend(hcd, do_wakeup);
> +	/* Only call ehci_suspend if ehci_setup has been done */
> +	if (ehci->sbrn)
> +		return ehci_suspend(hcd, do_wakeup);
> +
> +	return 0;
>  }
>  
>  static int ehci_msm_pm_resume(struct device *dev)
>  {
>  	struct usb_hcd *hcd = dev_get_drvdata(dev);
> +	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
>  
>  	dev_dbg(dev, "ehci-msm PM resume\n");
> -	ehci_resume(hcd, false);
> +
> +	/* Only call ehci_resume if ehci_setup has been done */
> +	if (ehci->sbrn)
> +		ehci_resume(hcd, false);
>  
>  	return 0;
>  }
> +
>  #else
>  #define ehci_msm_pm_suspend	NULL
>  #define ehci_msm_pm_resume	NULL

Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>