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Subject: Re: [PATCH 1/2] PCI: pciehp: Do not disable interrupt twice on
 suspend
From:   Kai-Heng Feng <kai.heng.feng@canonical.com>
In-Reply-To: <20190618125051.2382-1-mika.westerberg@linux.intel.com>
Date:   Fri, 21 Jun 2019 16:52:57 +0800
Cc:     Bjorn Helgaas <bhelgaas@google.com>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Lukas Wunner <lukas@wunner.de>,
        Keith Busch <keith.busch@intel.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Frederick Lawler <fred@fredlawl.com>,
        "Gustavo A . R . Silva" <gustavo@embeddedor.com>,
        Sinan Kaya <okaya@kernel.org>, linux-pci@vger.kernel.org,
        linux-kernel@vger.kernel.org
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Message-Id: <62F7BEE7-F38E-41C8-A181-B03F9308DE81@canonical.com>
References: <20190618125051.2382-1-mika.westerberg@linux.intel.com>
To:     Mika Westerberg <mika.westerberg@linux.intel.com>
Sender: linux-kernel-owner@vger.kernel.org
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at 20:50, Mika Westerberg <mika.westerberg@linux.intel.com> 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@canonical.com>
> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.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 */
>  };
> -- 
> 2.20.1