On Wed, 2011-09-14 at 14:18 +0530, K, Mythri P wrote: > On Wed, Sep 14, 2011 at 2:04 PM, Tomi Valkeinen <tomi.valkeinen@xxxxxx> wrote: > > On Wed, 2011-09-14 at 13:57 +0530, K, Mythri P wrote: > >> On Wed, Sep 14, 2011 at 12:44 PM, Tomi Valkeinen <tomi.valkeinen@xxxxxx> wrote: <snip> > > I don't understand this one. How could this be more dynamic? The > > function checks the HPD bit, which (based on my observation) shows the > > status whether a display is connected or not. > There is a GPIO which detects the +3.3V on the line and detects the > cable connect , there is also an interrupt based way.This is ideally > called a Hot-plug detect event according to the spec in HDMI terms. > But what you are saying here is that it is just a poll on the state? Yes, it's just for polling, but I don't quite see the difference. A hot-plug event notifies when the display is connected or disconnected, and detect() tells if a display is connected. They are all about the same thing. > >> So I said if the purpose of this function is only to check for the HPD > >> state bit it is fine. > > > > What does HPD bit tell us then? > > HPD state bit tells whether the cable is connected and whether EDID is This sounds like a good bit to test then. So is there something wrong with using HPD? How does the GPIO differ from HPD bit? > ready to be read, But this is a static check that is done in this > function. I don't understand what you mean with "static". The bit changes dynamically according to the connect/disconnect state, and the bit is checked dynamically when detect() is called. Tomi -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
