linux-kernel - Re: [PATCH 1/2] PCI: pciehp: Do not disable interrupt twice on suspend

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Date:   Mon, 24 Jun 2019 11:34:50 +0200
From:   "Rafael J. Wysocki" <rjw@...ysocki.net>
To:     Mika Westerberg <mika.westerberg@...ux.intel.com>
Cc:     Bjorn Helgaas <bhelgaas@...gle.com>,
        Lukas Wunner <lukas@...ner.de>,
        Keith Busch <keith.busch@...el.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Frederick Lawler <fred@...dlawl.com>,
        "Gustavo A . R . Silva" <gustavo@...eddedor.com>,
        Sinan Kaya <okaya@...nel.org>,
        Kai Heng Feng <kai.heng.feng@...onical.com>,
        linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] PCI: pciehp: Do not disable interrupt twice on suspend

On Tuesday, June 18, 2019 2:50:50 PM CEST Mika Westerberg wrote:
> We try to keep PCIe hotplug ports runtime suspended when entering system
> suspend. Due to the fact that the PCIe portdrv sets NEVER_SKIP driver PM
> flag the PM core always calls system suspend/resume hooks even if the
> device is left runtime suspended. Since PCIe hotplug driver re-uses the
> same function for both it ends up disabling hotplug interrupt twice and
> the second time following is printed:
> 
>   pciehp 0000:03:01.0:pcie204: pcie_do_write_cmd: no response from device
> 
> Prevent this from happening by checking whether the device is already
> runtime suspended when system suspend hook is called.
> 
> Fixes: 9c62f0bfb832 ("PCI: pciehp: Implement runtime PM callbacks")
> Reported-by: Kai Heng Feng <kai.heng.feng@...onical.com>
> Signed-off-by: Mika Westerberg <mika.westerberg@...ux.intel.com>

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

> ---
>  drivers/pci/hotplug/pciehp_core.c | 25 +++++++++++++++++++++++--
>  1 file changed, 23 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
> index 6ad0d86762cb..3f8c13ddb3e8 100644
> --- a/drivers/pci/hotplug/pciehp_core.c
> +++ b/drivers/pci/hotplug/pciehp_core.c
> @@ -248,7 +248,7 @@ static bool pme_is_native(struct pcie_device *dev)
>  	return pcie_ports_native || host->native_pme;
>  }
>  
> -static int pciehp_suspend(struct pcie_device *dev)
> +static void pciehp_disable_interrupt(struct pcie_device *dev)
>  {
>  	/*
>  	 * Disable hotplug interrupt so that it does not trigger
> @@ -256,7 +256,19 @@ static int pciehp_suspend(struct pcie_device *dev)
>  	 */
>  	if (pme_is_native(dev))
>  		pcie_disable_interrupt(get_service_data(dev));
> +}
>  
> +#ifdef CONFIG_PM_SLEEP
> +static int pciehp_suspend(struct pcie_device *dev)
> +{
> +	/*
> +	 * If the port is already runtime suspended we can keep it that
> +	 * way.
> +	 */
> +	if (dev_pm_smart_suspend_and_suspended(&dev->port->dev))
> +		return 0;
> +
> +	pciehp_disable_interrupt(dev);
>  	return 0;
>  }
>  
> @@ -274,6 +286,7 @@ static int pciehp_resume_noirq(struct pcie_device *dev)
>  
>  	return 0;
>  }
> +#endif
>  
>  static int pciehp_resume(struct pcie_device *dev)
>  {
> @@ -287,6 +300,12 @@ static int pciehp_resume(struct pcie_device *dev)
>  	return 0;
>  }
>  
> +static int pciehp_runtime_suspend(struct pcie_device *dev)
> +{
> +	pciehp_disable_interrupt(dev);
> +	return 0;
> +}
> +
>  static int pciehp_runtime_resume(struct pcie_device *dev)
>  {
>  	struct controller *ctrl = get_service_data(dev);
> @@ -313,10 +332,12 @@ static struct pcie_port_service_driver hpdriver_portdrv = {
>  	.remove		= pciehp_remove,
>  
>  #ifdef	CONFIG_PM
> +#ifdef	CONFIG_PM_SLEEP
>  	.suspend	= pciehp_suspend,
>  	.resume_noirq	= pciehp_resume_noirq,
> +#endif
>  	.resume		= pciehp_resume,
> -	.runtime_suspend = pciehp_suspend,
> +	.runtime_suspend = pciehp_runtime_suspend,
>  	.runtime_resume	= pciehp_runtime_resume,
>  #endif	/* PM */
>  };
>