Re: [PATCH] PCI / PM: Fix messages printed by acpi_pci_set_power_state()

From: Alan Stern <stern@rowland.harvard.edu>
To: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Bjorn Helgaas" <bhelgaas@google.com>,
	"huang ying" <huang.ying.caritas@gmail.com>,
	"Bjørn Mork" <bjorn@mork.no>, "Huang Ying" <ying.huang@intel.com>,
	"Zheng Yan" <zheng.z.yan@intel.com>,
	linux-pci@vger.kernel.org, linux-usb@vger.kernel.org,
	"Linux PM list" <linux-pm@vger.kernel.org>
Subject: Re: [PATCH] PCI / PM: Fix messages printed by acpi_pci_set_power_state()
Date: Wed, 25 Jul 2012 16:02:55 -0400 (EDT)	[thread overview]
Message-ID: <Pine.LNX.4.44L0.1207251600500.2008-100000@iolanthe.rowland.org> (raw)
In-Reply-To: <201207252151.14069.rjw@sisk.pl>

On Wed, 25 Jul 2012, Rafael J. Wysocki wrote:

> 
> If a PCI device is put into D3_cold by acpi_bus_set_power(),
> the message printed by acpi_pci_set_power_state() says that its
> power state has been changed to D4, which doesn't make sense.
> In turn, if the device is put into D3_hot, the message says just
> "D3" without specifying which variant of D3 it is.
> 
> Fix that by using an array of state names corresponding to the
> PCI device power states instead of building the state name from
> the numeric value corresponding to the given state directly.
> 
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> ---
>  drivers/pci/pci-acpi.c |   14 +++++++++++---
>  1 file changed, 11 insertions(+), 3 deletions(-)
> 
> Index: linux/drivers/pci/pci-acpi.c
> ===================================================================
> --- linux.orig/drivers/pci/pci-acpi.c
> +++ linux/drivers/pci/pci-acpi.c
> @@ -265,9 +265,17 @@ static int acpi_pci_set_power_state(stru
>  		error = acpi_bus_set_power(handle, state_conv[state]);
>  	}
>  
> -	if (!error)
> -		dev_printk(KERN_INFO, &dev->dev,
> -				"power state changed by ACPI to D%d\n", state);
> +	if (!error) {
> +		static const char *state_name[] = {
> +			[PCI_D0] = "D0",
> +			[PCI_D1] = "D1",
> +			[PCI_D2] = "D2",
> +			[PCI_D3hot] = "D3hot",
> +			[PCI_D3cold] = "D3cold"
> +		};
> +		dev_info(&dev->dev, "power state changed by ACPI to %s\n",
> +			 state_name[state]);
> +	}

How about using the pci_power_name macro defined in
include/linux/pci.h instead?

Alan Stern