On 10/14/2012 04:41 AM, Bruno Pr?mont wrote: > Hi Mark, > > On Sat, 13 October 2012 Mark Hounschell <dmarkh at cfl.rr.com> wrote: >> On 10/13/2012 02:57 PM, Mark Hounschell wrote: >>> On 10/12/2012 05:14 PM, Bruno Pr?mont wrote: >>>>> TV - LG 42lb9df >>>>> PC - intel DH77DF motherboard >>>> >>> I have another AMD based PC here with an nvidia card and HDMI port. Using >>> the nvidia driver, it boots up with no output to the tv until X starts. >>> Once X starts I get my kdm login screen. All is well except the resolution >>> is 800x600 and I have no VTs. I suspect if I had a properly configured >>> xorg.conf file, my resolution would be what I defined in it and work. >>> >>> Using the nouveau driver, I get nothing but "no signal" on the tv. Just >>> like the the intel box, except no EDID messages in the log file. I've >>> attached a dmesg outputs for each config. >>> >>> Back on the Intel machine. I boot up with a normal monitor connected to the >>> DVI port of the PC. Then at the kdm login screen, I disconnect the DVI >>> cable from the PC and connect the TV to the PCs DVI port using a DVI/HDMI >>> adapter. I get a beautiful 1600x1200 resolution screen on the TV. This does >>> not happen using the PC HDMI port. >>> >> >> One other thing I failed to mention. If i connect the TV HDMI to the Intel >> boards DVI port using the adapter, at power up I get all the BIOS messages >> and can enter the BIOS and all is fine. But when I let it boot all the way >> up like this, I get nothing but "no signal" after leaving BIOS mode. >> Turning the tv on/off, cable plug/unplug does not help. > > Did you also try the DVI-HDMI adapter cable with the nVidia card? > No, I didn't try that. I certainly can though. > But will all that info I would say the issues is at the side of you TV that > just does not provide (valid) EDID information, thus the driver does not know > what the display supports. > > The 1600x1200 when switching DVI displays on Intel would seem like the driver > just kept on display what it had, not reconfiguring anything. > Right, that's what I thought was happening. But at least it tells me that the tv can in fact "probably" operate in whatever resolution I force it to. Is there no way, like in the past we had to do, to just not care what the tv/monitor says or does, and just use a fixed resolution? > For the 800x600 of nVidia, that kind of the default fallback when display > capabilities are unknown as any remotely recent display should alt least be > capable to understand that. > Yep, that's what I figured here too. nvidia provides a "default/fallback" so you can at least access the desktop. Seems a reasonable thing, no? > > Your best solution is probably to write an EDID blob (or reuse one you find > somewhere) that provides at least one mode matching your TV's native mode > (probably full-HD). > > Google suggested the following document: > http://www.jordansmanuals.com/ServiceManuals%5CLG%5CTV%5CLCD%5C42LB9DF%5C42LB9DF%20Service%20Manual.pdf > which on page 13/14 shows the full EDID blob for the various HDMI outputs of the > TV. You may want to read that document, convert the EDID blobs to 512 bytes binary > files and hell DRM core to use the right one via module/kernel cmdline option: > > drm_kms_helper.edid_firmware=edid/lg42lb9df.edid > or > modprobe drm-kms-helper edid_firmware=edid/lg42lb9df.edid > > where > /lib/firmware/edid/lg42lb9df.edid > is the 512-bytes EDID blob created according to data from above manual. > (note, that will only work for intel, radeon and nouveau drivers but will > not work for closed drivers of AMD/nVidia) > Thanks for this tip. I will investigate this asap. > PS: If you didn't already do so, try all of the HDMI connectors or the TV and > if available, also two distinct HDMI cables of different brand. Did all that, first thing. Thanks Mark
