On Wednesday, January 22, 2014 2:04 PM, Liu Ying wrote: > > Ping... > > Regards, > Liu Ying Please, don't send the ping within 2 days. It is not a good practice. You sent the v1 patch 6 months ago. However, why I should review the patch within 2 days? Please wait. Best regards, Jingoo Han > > On 01/20/2014 12:52 PM, Liu Ying wrote: > > We don't have to turn backlight on/off everytime a blanking > > or unblanking event comes because the backlight status may > > have already been what we want. Another thought is that one > > backlight device may be shared by multiple framebuffers. We > > don't hope blanking one of the framebuffers may turn the > > backlight off for all the other framebuffers, since they are > > likely being active to display something. This patch adds > > some logics to record each framebuffer's backlight usage to > > determine the backlight device use count and whether the > > backlight should be turned on or off. To be more specific, > > only one unblank operation on a certain blanked framebuffer > > may increase the backlight device's use count by one, while > > one blank operation on a certain unblanked framebuffer may > > decrease the use count by one, because the userspace is > > likely to unblank a unblanked framebuffer or blank a blanked > > framebuffer. > > > > Signed-off-by: Liu Ying <Ying.Liu@xxxxxxxxxxxxx> > > --- > > v1 can be found at https://lkml.org/lkml/2013/5/30/139 > > > > v1->v2: > > * Make the commit message be more specific about the condition > > in which backlight device use count can be increased/decreased. > > * Correct the setting for bd->props.fb_blank. > > > > drivers/video/backlight/backlight.c | 28 +++++++++++++++++++++------- > > include/linux/backlight.h | 6 ++++++ > > 2 files changed, 27 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c > > index 5d05555..42044be 100644 > > --- a/drivers/video/backlight/backlight.c > > +++ b/drivers/video/backlight/backlight.c > > @@ -34,13 +34,15 @@ static const char *const backlight_types[] = { > > defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE)) > > /* This callback gets called when something important happens inside a > > * framebuffer driver. We're looking if that important event is blanking, > > - * and if it is, we're switching backlight power as well ... > > + * and if it is and necessary, we're switching backlight power as well ... > > */ > > static int fb_notifier_callback(struct notifier_block *self, > > unsigned long event, void *data) > > { > > struct backlight_device *bd; > > struct fb_event *evdata = data; > > + int node = evdata->info->node; > > + int fb_blank = 0; > > > > /* If we aren't interested in this event, skip it immediately ... */ > > if (event != FB_EVENT_BLANK && event != FB_EVENT_CONBLANK) > > @@ -51,12 +53,24 @@ static int fb_notifier_callback(struct notifier_block *self, > > if (bd->ops) > > if (!bd->ops->check_fb || > > bd->ops->check_fb(bd, evdata->info)) { > > - bd->props.fb_blank = *(int *)evdata->data; > > - if (bd->props.fb_blank == FB_BLANK_UNBLANK) > > - bd->props.state &= ~BL_CORE_FBBLANK; > > - else > > - bd->props.state |= BL_CORE_FBBLANK; > > - backlight_update_status(bd); > > + fb_blank = *(int *)evdata->data; > > + if (fb_blank == FB_BLANK_UNBLANK && > > + !bd->fb_bl_on[node]) { > > + bd->fb_bl_on[node] = true; > > + if (!bd->use_count++) { > > + bd->props.state &= ~BL_CORE_FBBLANK; > > + bd->props.fb_blank = FB_BLANK_UNBLANK; > > + backlight_update_status(bd); > > + } > > + } else if (fb_blank != FB_BLANK_UNBLANK && > > + bd->fb_bl_on[node]) { > > + bd->fb_bl_on[node] = false; > > + if (!(--bd->use_count)) { > > + bd->props.state |= BL_CORE_FBBLANK; > > + bd->props.fb_blank = FB_BLANK_POWERDOWN; > > + backlight_update_status(bd); > > + } > > + } > > } > > mutex_unlock(&bd->ops_lock); > > return 0; > > diff --git a/include/linux/backlight.h b/include/linux/backlight.h > > index 5f9cd96..7264742 100644 > > --- a/include/linux/backlight.h > > +++ b/include/linux/backlight.h > > @@ -9,6 +9,7 @@ > > #define _LINUX_BACKLIGHT_H > > > > #include <linux/device.h> > > +#include <linux/fb.h> > > #include <linux/mutex.h> > > #include <linux/notifier.h> > > > > @@ -104,6 +105,11 @@ struct backlight_device { > > struct list_head entry; > > > > struct device dev; > > + > > + /* Multiple framebuffers may share one backlight device */ > > + bool fb_bl_on[FB_MAX]; > > + > > + int use_count; > > }; > > > > static inline void backlight_update_status(struct backlight_device *bd) > > -- > > 1.7.9.5 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
