Re: [PATCH] backlight: pwm_bl: move suspend/resume entries fromplatform_driver to driver.pm

[Barry Song]

2011/12/1 Eric Miao <eric.y.miao@xxxxxxxxx>:
> On Thu, Dec 1, 2011 at 9:53 AM, Barry Song <Barry.Song@xxxxxxx> wrote:
>> From: Xiangzhen Ye <Xiangzhen.Ye@xxxxxxx>
>>
>> At first, people are moving suspend/resume entries from platform_driver
>> to driver.pm for many drivers.
>> On the other hand, if we use swsusp to do hibernation for an embedded
>> system using pwm_bl, in the process of preparing snapshot, backlight
>> will be off and make lcd black screen. This gives bad user experiences.
>> This patch will fix this issue as swsusp will go to call pm.freeze()
>> but not platform_driver.suspend. we have no pm.freeze() for pwm_bl, so
>> the lcd black screen will disappear.
>>
>> Signed-off-by: Xiangzhen Ye <Xiangzhen.Ye@xxxxxxx>
>> Signed-off-by: Barry Song <Baohua.Song@xxxxxxx>
>
> Acked-by: Eric Miao <eric.y.miao@xxxxxxxxx>

Eric, thanks. Mark Brown's "backlight: convert pwm_bl to dev_pm_ops"
http://www.spinics.net/lists/mm-commits/msg86844.html
did seem and has been merged as commit e2c17bc6f.


>
>> ---
>> Âdrivers/video/backlight/pwm_bl.c | Â 15 ++++++++++-----
>> Â1 files changed, 10 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
>> index 8b5b2a4..50f3134 100644
>> --- a/drivers/video/backlight/pwm_bl.c
>> +++ b/drivers/video/backlight/pwm_bl.c
>> @@ -169,9 +169,9 @@ static int pwm_backlight_remove(struct platform_device *pdev)
>> Â}
>>
>> Â#ifdef CONFIG_PM
>> -static int pwm_backlight_suspend(struct platform_device *pdev,
>> - Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Âpm_message_t state)
>> +static int pwm_backlight_suspend(struct device *dev)
>> Â{
>> + Â Â Â struct platform_device *pdev = to_platform_device(dev);
>> Â Â Â Âstruct backlight_device *bl = platform_get_drvdata(pdev);
>> Â Â Â Âstruct pwm_bl_data *pb = dev_get_drvdata(&bl->dev);
>>
>> @@ -184,8 +184,9 @@ static int pwm_backlight_suspend(struct platform_device *pdev,
>> Â Â Â Âreturn 0;
>> Â}
>>
>> -static int pwm_backlight_resume(struct platform_device *pdev)
>> +static int pwm_backlight_resume(struct device *dev)
>> Â{
>> + Â Â Â struct platform_device *pdev = to_platform_device(dev);
>> Â Â Â Âstruct backlight_device *bl = platform_get_drvdata(pdev);
>>
>> Â Â Â Âbacklight_update_status(bl);
>> @@ -196,15 +197,19 @@ static int pwm_backlight_resume(struct platform_device *pdev)
>> Â#define pwm_backlight_resume  NULL
>> Â#endif
>>
>> +static const struct dev_pm_ops pwm_backlight_pm_ops = {
>> + Â Â Â .suspend = pwm_backlight_suspend,
>> + Â Â Â .resume = pwm_backlight_resume,
>> +};
>> +
>> Âstatic struct platform_driver pwm_backlight_driver = {
>>    Â.driver     = {
>>        Â.name  = "pwm-backlight",
>> Â Â Â Â Â Â Â Â.owner Â= THIS_MODULE,
>> +        .pm   = &pwm_backlight_pm_ops,
>> Â Â Â Â},
>>    Â.probe     Â= pwm_backlight_probe,
>>    Â.remove     = pwm_backlight_remove,
>> -    .suspend    Â= pwm_backlight_suspend,
>> -    .resume     = pwm_backlight_resume,
>> Â};
>>
>> Âstatic int __init pwm_backlight_init(void)
>> --
>> 1.7.1

-barry
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