linux-kernel - Re: [PATCH v3 1/2] PCI: pciehp: Do not disable interrupt twice on suspend

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Date:   Tue, 12 Nov 2019 11:32:14 +0200
From:   Mika Westerberg <mika.westerberg@...ux.intel.com>
To:     Bjorn Helgaas <bhelgaas@...gle.com>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:     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 v3 1/2] PCI: pciehp: Do not disable interrupt twice on
 suspend

Hi Bjorn,

Friendly reminder. If there are no objections it would be nice to get
these two into v5.5 so we would have mostly working native PCIe hotlug
then :)

On Tue, Oct 29, 2019 at 08:00:21PM +0300, 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>
> Tested-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>
> ---
> No changes from previous version.
> 
>  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 b3122c151b80..56daad828c9e 100644
> --- a/drivers/pci/hotplug/pciehp_core.c
> +++ b/drivers/pci/hotplug/pciehp_core.c
> @@ -253,7 +253,7 @@ 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
> @@ -261,7 +261,19 @@ 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;
>  }
>  
> @@ -279,6 +291,7 @@ static int pciehp_resume_noirq(struct pcie_device *dev)
>  
>  	return 0;
>  }
> +#endif
>  
>  static int pciehp_resume(struct pcie_device *dev)
>  {
> @@ -292,6 +305,12 @@ 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);
> @@ -318,10 +337,12 @@ 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,
>  	.resume		= pciehp_resume,
> -	.runtime_suspend = pciehp_suspend,
> +#endif
> +	.runtime_suspend = pciehp_runtime_suspend,
>  	.runtime_resume	= pciehp_runtime_resume,
>  #endif	/* PM */
>  };
> -- 
> 2.23.0