On Fri, Jan 10, 2014 at 02:37:40PM +0200, Tomi Valkeinen wrote: > I don't think this is better than the previous version where > FB_SYNC_DE_HIGH_ACT and FB_SYNC_PIXDAT_HIGH_ACT were in > include/uapi/linux/fb.h. Now those flag defines are not visible to the > userspace, but the actual flags are still visible from the var->sync field. > > It's true what Russell replied to the previous version, that the > userspace has no idea how to handle those new flags. But then again, for > LCDs, the userspace has no idea how to handle, say, hsync polarity either. > > In any case, splitting the FB_SYNC_ defines into uapi and > kernel-internal header files, but still giving the kernel-internal > values to userspace is surely wrong.
The difference between the sync states and these other flags is that the sync states are part of the mode definition - as per the CEA-861 documentation. However, that does not extend to LCD panels, which generally need to have one set of timings, with the various control signals at certain polarities - and those control signal polarities are a property of the panel itself, not of the displayed mode. So, if you know that you have LCD panel X, and it needs control signals with a certain polarity, that is how you configure the hardware _irrespective_ of what userspace says that the sync states should be. The sync states specified by userspace should of course be used for the sync pulses being sent to a VGA display or HDMI sink. -- FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up. Estimation in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad. Estimate before purchase was "up to 13.2Mbit". -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
