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Author Topic: KMS woes  (Read 2859 times)

Offline sigtec

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KMS woes
« on: August 18, 2011, 01:23:17 AM »
Hi all,

I am trying to use tinycore (well microcore) for a project, and I am having huge problems. I need to get 1920x1080 rotated display (ie. portrait). I have tried Xvesa with 915resolution - can't get 1920x1080 as HSync and VSync can't be defined. I have patched 915resolution to allow the modeline to be specified. I have tried Xfbdev - can't specify 1920x1080, and can't set the mode after using the "vga=xxx" kernel argument. Xorg will display 1920x1080 using the vesa driver, but not i915. Can't rotate with the vesa driver. Trying to use i915 gets "no kernel modesetting driver detected". Tried Xorg-7.4, Xorg-7.5, Xorg-7.5-3d (with all the associated other required stuff). Recompiled the kernel with KMS turned off, then with KMS turned on (tried both module and built in). Has anyone *ever* had KMS working on TC? We are using 3.5.1 with kernel 2.6.33.3-tinycore #3

My hardware: Nano-9452, celeron M, intel 945GME, Samsung syncmaster 2233sw monitor.

Tinycore fits the bill perfectly for all the other hardware configs (eg. LED panel rather than VGA out), just no luck with VGA. The customer has specified the panel, so I can't change that.

Thanks for the help....

Offline curaga

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Re: KMS woes
« Reply #1 on: August 18, 2011, 02:31:28 AM »
You don't say what happens when you try to use intel KMS, either with your own build or via loading the graphics- extension (a dep of Xorg-7.5-3d).
The only barriers that can stop you are the ones you create yourself.

Online Juanito

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Re: KMS woes
« Reply #2 on: August 18, 2011, 03:02:38 AM »
kms is working fine for me with Xorg-7.5, the intel driver and this hardware:
Code: [Select]
00:02.0 VGA compatible controller: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03)
00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller (rev 03)

Offline sigtec

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Re: KMS woes
« Reply #3 on: August 18, 2011, 07:15:13 PM »
Sorry, didn't explain what happens with KMS.

Using the default Xorg (ie. no xorg.conf), we get:

(EE) open /dev/fb0: No such device        <- expected as KMS and framebuffer clash, so no vga= parameter for the kernel
(EE) intel(0): No kernel modesetting driver detected
(EE) Screens(s) found, but none have a usable configuration

Fatal server error:
no screens found


Now, doing an Xorg -configure, editing the conf to use the vesa driver, and using the correct modeline, I can get 1920x1080. However, the vesa driver won't rotate (ie. either using xrandr or the rotate option in xorg.conf). Now I have tried:

i915.modeset=1, and
i915.modeset=0

on the kernel line (from grub)

and added /etc/modprobe.d/915.conf, with:
options i915 modeset=1, and
options i915 modeset=0

(ie. tried both, but not at the same time obviously).

I booted a live version of mint, and grabbed the modeline, so I know it is correct. When using 915resolution (and vesa), you can't specify the sync polarity (ie. hsync and vsync), so although the card will go into 1920x1080, it won't display on the monitor. The vesa server (Xvesa) will happily rotate a lower res, eg. Xvesa -screen 1280x1024x24@270, but won't work with 1920x1080 because of the incorrect sync polarities (checked the DPMS reported modes in mint).

I tried to get 7.4 working (non KMS) but haven't (yet) got the non KMS drivers. I might just have to go back to a 2.x version. The reason I used microcore is that I have a 32M card on which the OS and app/data has to sit :)

Cheers...

Offline sigtec

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[SOLVED] Re: KMS woes
« Reply #4 on: August 19, 2011, 01:51:08 AM »
Don't worry, found a solution. I hacked 915resolution so that you could specify the complete modeline (including hsync and vsync), which then added the EDID mode directly to the Vesa BIOS. I now have pristine 1920x1080 mode rotated 270 degrees!

KMS was a lost cause :(

Cheers,