linux-kernel - Re: [PATCH v5 1/3] PCI: rockchip: Add support for pcie wake irq

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Message-ID: <20171013030441.GA25517@bhelgaas-glaptop.roam.corp.google.com>
Date:   Thu, 12 Oct 2017 22:04:41 -0500
From:   Bjorn Helgaas <helgaas@...nel.org>
To:     Jeffy Chen <jeffy.chen@...k-chips.com>
Cc:     linux-kernel@...r.kernel.org, bhelgaas@...gle.com,
        Heiko Stuebner <heiko@...ech.de>, linux-pci@...r.kernel.org,
        shawn.lin@...k-chips.com, briannorris@...omium.org,
        dianders@...omium.org, linux-rockchip@...ts.infradead.org,
        linux-arm-kernel@...ts.infradead.org,
        "Rafael J. Wysocki" <rjw@...ysocki.net>, linux-pm@...r.kernel.org
Subject: Re: [PATCH v5 1/3] PCI: rockchip: Add support for pcie wake irq

[+cc Rafael, linux-pm]

On Mon, Sep 11, 2017 at 11:10:27PM +0800, Jeffy Chen wrote:
> Add support for PCIE_WAKE pin in rockchip pcie driver.
> 
> Signed-off-by: Jeffy Chen <jeffy.chen@...k-chips.com>
> ---
> 
> Changes in v5:
> Rebase
> 
> Changes in v3:
> Fix error handling
> 
> Changes in v2:
> Use dev_pm_set_dedicated_wake_irq
>         -- Suggested by Brian Norris <briannorris@...omium.com>
> 
>  drivers/pci/host/pcie-rockchip.c | 19 +++++++++++++++++--
>  1 file changed, 17 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/host/pcie-rockchip.c b/drivers/pci/host/pcie-rockchip.c
> index 9051c6c8fea4..a8b7272597a7 100644
> --- a/drivers/pci/host/pcie-rockchip.c
> +++ b/drivers/pci/host/pcie-rockchip.c
> @@ -37,6 +37,7 @@
>  #include <linux/pci_ids.h>
>  #include <linux/phy/phy.h>
>  #include <linux/platform_device.h>
> +#include <linux/pm_wakeirq.h>
>  #include <linux/reset.h>
>  #include <linux/regmap.h>
>  
> @@ -995,6 +996,15 @@ static int rockchip_pcie_setup_irq(struct rockchip_pcie *rockchip)
>  		return err;
>  	}
>  
> +	/* Must init wakeup before setting dedicated wakeup irq. */
> +	device_init_wakeup(dev, true);
> +	irq = platform_get_irq_byname(pdev, "wakeup");
> +	if (irq >= 0) {
> +		err = dev_pm_set_dedicated_wake_irq(dev, irq);

I'm a little skeptical about dev_pm_set_dedicated_wake_irq(), not
because I know anything at all about it, but because there are only
five callers in the whole tree, three of which are in UART code, and
none in anything resembling PCI code.

Is Rockchip really that special, or are we going about this the wrong
way?

> +		if (err)
> +			dev_err(dev, "failed to setup PCIe wakeup IRQ\n");
> +	}
> +
>  	return 0;

The above could be structured as:

  irq = platform_get_irq_byname(pdev, "wakeup");
  if (irq < 0)
    return 0;

  device_init_wakeup(dev, true);
  err = dev_pm_set_dedicated_wake_irq(dev, irq);
  if (err) {
    dev_pm_clear_wake_irq(dev);
    device_init_wakeup(dev, false);
  }

  return 0;

to unindent the mainline non-error code.

>  }
>  
> @@ -1542,11 +1552,11 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
>  
>  	err = rockchip_pcie_parse_dt(rockchip);
>  	if (err)
> -		return err;
> +		goto err_disable_wake;
>  
>  	err = rockchip_pcie_enable_clocks(rockchip);
>  	if (err)
> -		return err;
> +		goto err_disable_wake;
>  
>  	err = rockchip_pcie_set_vpcie(rockchip);
>  	if (err) {
> @@ -1656,6 +1666,9 @@ static int rockchip_pcie_probe(struct platform_device *pdev)
>  		regulator_disable(rockchip->vpcie0v9);
>  err_set_vpcie:
>  	rockchip_pcie_disable_clocks(rockchip);
> +err_disable_wake:
> +	dev_pm_clear_wake_irq(dev);
> +	device_init_wakeup(dev, false);

I think this error cleanup should be done in rockchip_pcie_setup_irq()
as shown above.  There's no real connection between
rockchip_pcie_probe() and the wake setup.

>  	return err;
>  }
>  
> @@ -1682,6 +1695,8 @@ static int rockchip_pcie_remove(struct platform_device *pdev)
>  	if (!IS_ERR(rockchip->vpcie0v9))
>  		regulator_disable(rockchip->vpcie0v9);
>  
> +	dev_pm_clear_wake_irq(dev);
> +	device_init_wakeup(dev, false);
>  	return 0;
>  }
>  
> -- 
> 2.11.0
> 
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

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