Hi Tomi, Tomi Valkeinen wrote on 2013-02-07: > FIFO underflow means that the DSS hardware wasn't able to fetch enough > pixel data in time to output them to the panel. Sometimes this happens > because of plain misconfiguration, but usually it happens because of > the hardware just can't do things fast enough with the configuration > the user has set. > > In this case I see that you are using VRFB rotation on fb0, and the > rotation is > 270 degrees. Rotating the fb is heavy, especially 90 and 270 degrees. > It may be that when the DSS is resumed, there's a peak in the mem > usage as DSS suddenly needs to fetch lots of data. > > Another issue that could be involved is power management. After the > DSS is suspended, parts of OMAP may be put to sleep. When the DSS is > resumed, these parts need to be woken up, and it may be that there's a > higher mem latency for a short period of time right after resume. > Which could again cause DSS not getting enough pixel data. > > You say the issue doesn't happen if you disable fb0. What happens if > you disable fb0, blank the screen, then unblank the screen, and after > that enable fb0 again? By "disable fb0" do you mean disconnect fb0 from ovl0 or disable ovl0? I have done both: http://pastebin.com/Bxm1Z2RY This works as expected. Further tests I have done: Enable fb1/ovl1 and hit some keys on the keyboard to let fb0/ovl0 update in the background causes a fifo underflow too: http://pastebin.com/f3JnMLsV This happens only, if I enable the vrfb (rotate=3). So the whole thing seems to be a rotation issue. Do you have some hints to trace down the problem? > How about if you disable VRFB rotation, either totally, or set the > rotation to 0 or 180 degrees? Disable rotation is not an option for me, as we have a "wrong" oriented portrait display with 480x800 which we must use in landscape mode... > And you can also tune the PM so that deeper sleep states are prevented. > I don't remember right away how this is done, though. > > Tomi Regards, Florian P.S. @Laurent: Do you use your streamer on a headless device? What is your DSS-config? Do you have a framebuffer-console on fb0? -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
