Am 07.02.2014 um 16:15 schrieb Michael Mrozek:
Am Fri, 7 Feb 2014 15:56:03 +0100 hat "Dr. H. Nikolaus Schaller" hns@goldelico.com geschrieben:
Hi,
wow, thanks, great work :D
About the black panel:
The Renesas chip seems to have pattern generator included: http://www.rsp.renesas.com/en/news/2012/news20120418.htm
Do we know how we can trigger that?
Great idea!
Unfortunately no. It is not described in the panel data sheet. And we have no data sheet for the Renesas chip. Maybe the other one has something similar.
It could even be something as simple as a black framebuffer contents :) But I don't think so since I did look a little at the output signals and it looks more like non-black pixel data.
It would at least help telling us if the initial sequence starting the panel and timings are the issue or whether it is the picture transmission itself.
My idea for further debugging is to get the backlight control working. The intensity is driven by the panel and can be controlled through some MIPI command.
So as soon as I can write and read back the intensity, the communication should be working basically.
What I currently suspect is that the enabling sequence has some bug. And therefore the panel refuses to accept to turn on backlight and refuses to return the actual_brightness...
But Panel still remains black. So let's address the next road-block :)
Still black - but for the first time I can "detect" if a panel is connected... I.e. some communication is working:
With panel connected:
root@gta04:~# root@cat /sys/devices/ocp.3/dss.10/0.dsi/display0/backlight/r63311/actual_brightness [ 414.299407] dsi: r63311_get_brightness() [ 414.311004] omapdss DSI error: dsi_vc_read_rx_fifo(ch 1 type DCS) failed [ 414.318481] omapdss DSI error: dsi_vc_dcs_read(ch 1, cmd 0x52) failed [ 414.325592] r63311 display0: read cmd/reg(0) failed: -5 [ 414.331756] dsi: -5=r63311_read(00) [ 414.335784] dsi: read 0
With no panel connected:
root@gta04:~# root@cat /sys/devices/ocp.3/dss.10/0.dsi/display0/backlight/r63311/actual_brightness [ 263.789581] dsi: r63311_get_brightness() [ 264.292175] omapdss DSI error: Failed to receive BTA [ 264.297393] omapdss DSI error: dsi_vc_dcs_read(ch 1, cmd 0x52) failed [ 264.304229] r63311 display0: read cmd/reg(0) failed: -5 [ 264.309783] dsi: -5=r63311_read(00) [ 264.313476] dsi: read 0
You see the difference?
It is "Failed to receive BTA"
BTA is the MIPI abbreviation for "bus turn around". This means if the panel is connected it responds by sending data back to the OMAP. If it is not connected, that fails of course...
Ok, this is a strong indication that the electrical things (almost) work - but still may be one more roadblock.
And that there is something in the programming sequence for the panel after power-on.
BR, Nikolaus
Kernel mailing list Kernel@pyra-handheld.com http://pyra-handheld.com/cgi-bin/mailman/listinfo/kernel
-- Mit freundlichen Grüßen,
Michael Mrozek
OpenPandora GmbH Geschäftsführer: Michael Mrozek
Schäffbräustr. 11 85049 Ingolstadt Deutschland Tel.: 0841 / 13 177 33 http://www.openpandora.de/ HRB 4879, Amtsgericht Ingolstadt
ICQ: 15691903 MSN: EvilDragon1717@hotmail.com eMail: info@openpandora.de _______________________________________________ Kernel mailing list Kernel@pyra-handheld.com http://pyra-handheld.com/cgi-bin/mailman/listinfo/kernel