On Friday, November 01, 2013 6:58 PM, Thierry Reding wrote: > On Fri, Nov 01, 2013 at 08:44:48AM +0900, Jingoo Han wrote: >> On Friday, October 25, 2013 10:58 PM, Laurent Pinchart wrote: >>> On Thursday 24 October 2013 13:05:25 Thierry Reding wrote: [....] >>>> Or is there still a reason to have more than a single bit for backlight >>>> state? I don't know any hardware that actually makes a difference >>>> between FB_BLANK_NORMAL, FB_BLANK_VSYNC_SUSPEND, FB_BLANK_HSYNC_SUSPEND >>>> or FB_BLANK_POWERDOWN. >> >> On Exynos side, I have never seen that FB_BLANK_VSYNC_SUSPEND, >> FB_BLANK_HSYNC_SUSPEND are used for controlling display panels or >> Display controllers. >> >> However, I heard that FB_BLANK_VSYNC_SUSPEND, FB_BLANK_HSYNC_SUSPEND are >> used for some monitors. > > I think that those may make sense in the context of fbdev, and looking > at some fbdev drivers seems to substantiate that. > > However, I don't think backlights have any such capability. I mean they > are either on or off, right? There's no such thing as partially off, or > partially on. How would a backlight behave differently if the panel was > in HSYNC suspend mode or VSYNC suspend mode? Hi Thierry Reding. I agree with you. In the case of backlight, there is no need that a backlight behaves differently in HSYNC suspend mode or VSYNC suspend mode. Best regards, Jingoo Han -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
