linux-kernel - Re: [PATCH] i915: slow acpi_lid

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Message-ID: <4B676B20.8060808@gmail.com>
Date:	Mon, 01 Feb 2010 16:00:32 -0800
From:	"Justin P. Mattock" <justinmattock@...il.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
CC:	Thomas Meyer <thomas@...3r.de>,
	Jesse Barnes <jbarnes@...tuousgeek.org>,
	Eric Anholt <eric@...olt.net>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	"Rafael J. Wysocki" <rjw@...k.pl>
Subject: Re: [PATCH] i915: slow acpi_lid_open() causes flickering

On 02/01/10 14:33, Andrew Morton wrote:
> On Mon, 01 Feb 2010 19:20:53 +0100
> Thomas Meyer<thomas@...3r.de>  wrote:
>
>> acpi_lid_open() could take up to 10ms on my computer.
>> Some component is calling the drm GETCONNECTOR ioctl many times in a row.
>> This results in flickering (for example, when starting a video).
>> Fix it by assuming an always connected lid status.
>>
>> This fixes bug http://bugzilla.kernel.org/show_bug.cgi?id=14670
>>
>> ---
>>   drivers/gpu/drm/i915/intel_lvds.c |   15 ++++++++++++++-
>>   1 files changed, 14 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
>> index aa74e59..0f0779c 100644
>> --- a/drivers/gpu/drm/i915/intel_lvds.c
>> +++ b/drivers/gpu/drm/i915/intel_lvds.c
>> @@ -632,6 +632,18 @@ static const struct dmi_system_id bad_lid_status[] = {
>>   	{ }
>>   };
>>
>> +/* Some lid devices take a long time to report the lid status, assume they're connected*/
>> +static const struct dmi_system_id slow_lid_status[] = {
>> +	{
>> +		.ident = "Aspire 1810T",
>> +		.matches = {
>> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
>> +			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 1810T"),
>> +		},
>> +	},
>> +	{ }
>> +};
>> +
>>   /**
>>    * Detect the LVDS connection.
>>    *
>> @@ -643,7 +655,8 @@ static enum drm_connector_status intel_lvds_detect(struct drm_connector *connect
>>   {
>>   	enum drm_connector_status status = connector_status_connected;
>>
>> -	if (!acpi_lid_open()&&  !dmi_check_system(bad_lid_status))
>> +	if (!dmi_check_system(slow_lid_status)&&  !dmi_check_system(bad_lid_status))
>> +	    if (!acpi_lid_open())
>>   		status = connector_status_disconnected;
>>
>>   	return status;
>
> The patch is missing your Signed-off-by: line.  I cheekily added it.
> Please check Documentation/SubmittingPatches, let me know if you
> disagree with this, thanks.
>
> --
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>

I'm wondering if just adding your DMI entry to
bad_lid_status[] is all that is really needed.
(this way it saves bits in the kernel).

Justin P. Mattock
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