[PATCH] ACPI video: fix a poor error message

[PATCH] ACPI video: fix a poor error message

[Zhang Rui]

Fix a poor error message, according to comment
https://bugzilla.kernel.org/show_bug.cgi?id=16599#c3

CC: Robert Moore <robert.moore@intel.com>
CC: Thomas Renninger <trenn@suse.de> 
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
---
 drivers/acpi/video_detect.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Index: linux-2.6/drivers/acpi/video_detect.c
===================================================================
--- linux-2.6.orig/drivers/acpi/video_detect.c
+++ linux-2.6/drivers/acpi/video_detect.c
@@ -59,8 +59,8 @@ acpi_backlight_cap_match(acpi_handle han
 				  "support\n"));
 		*cap |= ACPI_VIDEO_BACKLIGHT;
 		if (ACPI_FAILURE(acpi_get_handle(handle, "_BQC", &h_dummy)))
-			printk(KERN_WARNING FW_BUG PREFIX "ACPI brightness "
-					"control misses _BQC function\n");
+			printk(KERN_WARNING FW_BUG PREFIX "could not find "
+					"required _BQC function\n");
 		/* We have backlight support, no need to scan further */
 		return AE_CTRL_TERMINATE;
 	}

Re: [PATCH] ACPI video: fix a poor error message

[Matthew Garrett]

On Tue, Aug 17, 2010 at 10:42:55AM +0800, Zhang Rui wrote:
>  		*cap |= ACPI_VIDEO_BACKLIGHT;
>  		if (ACPI_FAILURE(acpi_get_handle(handle, "_BQC", &h_dummy)))
> -			printk(KERN_WARNING FW_BUG PREFIX "ACPI brightness "
> -					"control misses _BQC function\n");
> +			printk(KERN_WARNING FW_BUG PREFIX "could not find "
> +					"required _BQC function\n");

I don't really like the "required". It's a spec requirement but the 
driver will work fine (if suboptimally) without it.

-- 
Matthew Garrett | mjg59@srcf.ucam.org

RE: [PATCH] ACPI video: fix a poor error message

[Moore, Robert]

Do we agree that the original message is unclear?

I'm not even sure that ACPI requires this method.

Perhaps the message should describe what won't happen because of the missing _BQC method.


>-----Original Message-----
>From: Matthew Garrett [mailto:mjg59@srcf.ucam.org]
>Sent: Tuesday, August 17, 2010 6:35 AM
>To: Zhang, Rui
>Cc: Brown, Len; linux-acpi@vger.kernel.org; Moore, Robert; Thomas Renninger
>Subject: Re: [PATCH] ACPI video: fix a poor error message
>
>On Tue, Aug 17, 2010 at 10:42:55AM +0800, Zhang Rui wrote:
>>  		*cap |= ACPI_VIDEO_BACKLIGHT;
>>  		if (ACPI_FAILURE(acpi_get_handle(handle, "_BQC", &h_dummy)))
>> -			printk(KERN_WARNING FW_BUG PREFIX "ACPI brightness "
>> -					"control misses _BQC function\n");
>> +			printk(KERN_WARNING FW_BUG PREFIX "could not find "
>> +					"required _BQC function\n");
>
>I don't really like the "required". It's a spec requirement but the
>driver will work fine (if suboptimally) without it.
>
>--
>Matthew Garrett | mjg59@srcf.ucam.org

Re: [PATCH] ACPI video: fix a poor error message

[Matthew Garrett]

On Tue, Aug 17, 2010 at 08:24:25AM -0700, Moore, Robert wrote:
> Do we agree that the original message is unclear?
> 
> I'm not even sure that ACPI requires this method.

Indeed, it's not actually on the list of required methods.

> Perhaps the message should describe what won't happen because of the missing _BQC method.

Perhaps just "No _BQC method: Unable to determine initial brightness"?

-- 
Matthew Garrett | mjg59@srcf.ucam.org

RE: [PATCH] ACPI video: fix a poor error message

[Moore, Robert]

I like this much better. Probably should drop the colon, so it looks something like:

[Firmware Bug]: ACPI: No _BQC method, cannot determine initial brightness

I leave the question as to whether this is an actual firmware bug to you guys.

Bob

>-----Original Message-----
>From: Matthew Garrett [mailto:mjg59@srcf.ucam.org]
>Sent: Tuesday, August 17, 2010 8:28 AM
>To: Moore, Robert
>Cc: Zhang, Rui; Brown, Len; linux-acpi@vger.kernel.org; Thomas Renninger
>Subject: Re: [PATCH] ACPI video: fix a poor error message
>
>On Tue, Aug 17, 2010 at 08:24:25AM -0700, Moore, Robert wrote:
>> Do we agree that the original message is unclear?
>>
>> I'm not even sure that ACPI requires this method.
>
>Indeed, it's not actually on the list of required methods.
>
>> Perhaps the message should describe what won't happen because of the
>missing _BQC method.
>
>Perhaps just "No _BQC method: Unable to determine initial brightness"?
>
>--
>Matthew Garrett | mjg59@srcf.ucam.org