Ironlake mobile and VGA-connected external monitor : no go

[ttcoder]

An external monitor would be a nice upgrade for this laptop, so I tried to connect a (loaned) LCD TV to the VGA socket (wonder if HDMI would make a difference ?). Configured the BIOS to redirect video output to VGA, booted into Haiku.

When app_server starts, the external monitor turns off. Oddly, the built-in (laptop) screen's backlight turns on, and remains on.

The work-around provided in #15241 does not seem to work for me (if I unplug the monitor when boot up begins, and reconnect it after a while, it remains off; maybe I'm missing something).

That monitor is usable in VESA fall-back video mode, though the resolutions listed in the Screen preflet are so-so. The EDID entries provided in "Supported Video Mode" are kinda bogus; the correct one is listed in "Additional Video Mode" but is not picked up by the VESA driver for some reason.

Biggest motivation is that VESA has no support for brightness adjustment, so I'm keen on making the intel_extreme driver work

[ttcoder]

Turns off external monitor, turns on backlist of internal

[ttcoder]

The attachement comment should read "turns on back-Light.."

The driver finds a Init Intel generation 5 GPU with PCH split. chipset. Finds info on "LVDS" (looking good) and on "Analog A" (crazy width/height values, maybe didn't convert inches to cm)

Oddly concludes with

intel_set_display_mode: Port configuration completed successfully!

I can also provide a VESA syslog, but that will be with 1280x1024 etc resolution

[ttcoder]

Turns out this laptop has no HDMI connector (I mistook a FireWire socket for HDMI) so this will be a VGA-only ticket indeed, for me. I'll keep playing with this screen for a couple more weeks before I return it.

[pulkomandy]

Replying to ttcoder:

Finds info on "LVDS" (looking good) and on "Analog A" (crazy width/height values, maybe didn't convert inches to cm)

From my experience a lot of monitors have broken/random values there. We don't really use them except for showing the dpi in screen preferences anyway.

That monitor is usable in VESA fall-back video mode, though the resolutions listed in the Screen preflet are so-so. The EDID entries provided in "Supported Video Mode" are kinda bogus; the correct one is listed in "Additional Video Mode" but is not picked up by the VESA driver for some reason.

The "additional video mode" comes from the EDID data in the display, there is no guarantee that the VESA BIOS will do anything with it, sadly. In VESA we are completely relying on the BIOS to provide us with the list of modes.

Oddly concludes with

intel_set_display_mode: Port configuration completed successfully!

That's what makes debugging difficult. If the driver noticed something was wrong, it would be easier to fix. Unfortunately everything appears to work fine, except the screen remains black.

In the new Intel devices, the design of the hardware has changed a bit. The idea is that the CPU outputs everything as essentially DisplayPort (called Flexible Display Interface, but it's very similar), and then that is converted to the various other outputs (VGA, HDMI, ...). This needs a quite different setup process. We are trying to do it according to Intel docs but must have missed some steps so far.

I have the same problem here (SandyBridge) and I hope to get my VGA display working someday.

[ttcoder]

Thanks for the background info on this ; well that makes me want to try out other monitors, in case I stumble on one that is more to the liking of the BIOS and VESA ; and to watch for progress on intel_extreme, which might end up being the one with best support (resolution, brightness) :-). I should close this soon, it would be pointless to keep open even after I return the monitor to his owner.

[korli]

Please check with a current nightly, and provide a syslog.

[korli]

Please check with a current nightly, and attach a syslog

[ttcoder]

I've moved on to a T430 (Ivy Bridge), and no longer have that particular monitor either, closing.

[korli]

thanks for the update!