linux-kernel - Re: [PATCH 4/5]pci:setup_bus.c Fix warning: variable 'retval' set but not used

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Date:	Fri, 18 Jun 2010 14:12:41 -0700
From:	"Justin P. Mattock" <justinmattock@...il.com>
To:	Jesse Barnes <jbarnes@...tuousgeek.org>
CC:	Yinghai Lu <yinghai@...nel.org>, linux-kernel@...r.kernel.org,
	linux-wireless@...r.kernel.org, linux-pci@...r.kernel.org,
	linux-scsi@...r.kernel.org
Subject: Re: [PATCH 4/5]pci:setup_bus.c Fix warning: variable 'retval' set
 but not used

On 06/18/2010 01:46 PM, Jesse Barnes wrote:
> On Fri, 18 Jun 2010 13:26:32 -0700
> "Justin P. Mattock"<justinmattock@...il.com>  wrote:
>
>> On 06/18/2010 01:05 PM, Jesse Barnes wrote:
>>> On Fri, 18 Jun 2010 12:59:32 -0700
>>> "Justin P. Mattock"<justinmattock@...il.com>   wrote:
>>>> just added this in(as a test), and the retval warning still shows up.
>>>> with the last post I just added a printk was that legit, and if so what
>>>> else might be added to it to make it complete and proper?
>>>
>>> What's the full warning?  Seems like printing the value should have
>>> been enough to shut up gcc...
>>>
>>
>> this is the warning messg after applying yinghai's patch:
>>
>>     CC      drivers/pci/setup-bus.o
>> drivers/pci/setup-bus.c: In function
>> 'pci_assign_unassigned_bridge_resources':
>> drivers/pci/setup-bus.c:868:6: warning: variable 'retval' set but not used
>
> Right because Yinghai's patch just sets retval but doesn't actually use
> it anywhere.
>

that's what is confusing..(not being used, but is being used, but gcc 
says it's not used..)  :-)

>> if I add a printk then gcc is content.. patch below, but not the best at
>> creating printk's(the whole % thing messes me up) but here goes:
>>
>>   From 48e15b87072c6b4286d943c55bfe2ae26d358795 Mon Sep 17 00:00:00 2001
>> From: Justin P. Mattock<justinmattock@...il.com>
>> Date: Fri, 18 Jun 2010 13:23:27 -0700
>> Subject: [PATCH 4/4] bus.c_add_print
>>    Signed-off-by: Justin P. Mattock<justinmattock@...il.com>
>>
>> ---
>>    drivers/pci/setup-bus.c |    1 +
>>    1 files changed, 1 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
>> index 66cb8f4..806b766 100644
>> --- a/drivers/pci/setup-bus.c
>> +++ b/drivers/pci/setup-bus.c
>> @@ -919,6 +919,7 @@ again:
>>
>>    enable_all:
>>    	retval = pci_reenable_device(bridge);
>> +	printk(KERN_DEBUG "PCI%d: re-enabling device\n", retval);
>>    	pci_set_master(bridge);
>>    	pci_enable_bridges(parent);
>>    }
>
> Again, this doesn't have the if (retval) condition around the printk; I
> don't want to see this message everytime regardless.  Also the message
> is misleading, it should be something like:
>    dev_err(&bridge->dev, "failed to re-enable device: %d\n", retval)
> instead.  PCI%d makes it look like we're talking about a specific bus
> or something and not an error code.
>

o.k. I admit I looked at other printk's in this file to get an idea of 
what I might do.. saw PCI%d and figured it would print
"PCI: re-enabling device"
but didnt think it was an error... reason for putting KERN_DEBUG.

here is what the new patch looks like:


 From f910375438be06497d0524bff146c26cafca272b Mon Sep 17 00:00:00 2001
From: Justin P. Mattock <justinmattock@...il.com>
Date: Fri, 18 Jun 2010 14:08:37 -0700
Subject: [PATCH 4/4] setup-pci_test
  Signed-off-by: Justin P. Mattock <justinmattock@...il.com>

---
  drivers/pci/setup-bus.c |    3 +++
  1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 66cb8f4..2ab5f1e 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -919,6 +919,9 @@ again:

  enable_all:
  	retval = pci_reenable_device(bridge);
+	if (retval) {
+		dev_err(&bridge->dev, "failed to re-enable device: %d\n", retval);
+	}
  	pci_set_master(bridge);
  	pci_enable_bridges(parent);
  }
-- 
1.7.1.rc1.21.gf3bd6


should I have put if (!retval) instead
should I put "failed to re-enable bridge device"
is there an exit code needed?

if not and all is good then I can resend this out..

Justin P. Mattock
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