Re: [PATCH 1/4] usb: hcd-pci: Honour pci_save_state() failure

[Alan Stern]

On Thu, Sep 24, 2026 at 09:42:18AM -0300, Francisco Beltrán Millalén wrote:
> hcd_pci_suspend_noirq() calls pci_save_state() and ignores its return
> value, then goes on to call pci_prepare_to_sleep().  pci_save_state()
> can fail -- it already propagates failures from pci_save_pcie_state()
> and friends -- and when it does there is no saved state to restore
> later, so putting the device into a low-power state only makes matters
> worse: the subsequent transition fails too, and the PCI core then warns
> that the callback returned without saving the state.
> 
> Check the return value.  If the state could not be saved, leave the
> device alone and return success, so the rest of the system can still
> suspend.  Leaving the power state untouched also means the PCI core has
> nothing to complain about.
> 
> Signed-off-by: Francisco Beltrán Millalén <fbeltranmillalen@xxxxxxxxx>
> ---

Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>

> diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
> --- a/drivers/usb/core/hcd-pci.c
> +++ b/drivers/usb/core/hcd-pci.c
> @@ -541,7 +541,17 @@
>  	if (retval)
>  		return retval;
>  
> -	pci_save_state(pci_dev);
> +	/*
> +	 * If the controller is already inaccessible, there is no state to
> +	 * save and nothing to put into a low-power state.  Leaving the power
> +	 * state alone also keeps the PCI core from warning that this callback
> +	 * returned without saving the state.
> +	 */
> +	retval = pci_save_state(pci_dev);
> +	if (retval) {
> +		dev_dbg(dev, "--> not suspending, device inaccessible\n");
> +		return 0;
> +	}
>  
>  	/* If the root hub is dead rather than suspended, disallow remote
>  	 * wakeup.  usb_hc_died() should ensure that both hosts are marked as
>