Custom resolution for intel GMA3150 (Intel NM10 Atom D525)

marcs · 2012-02-20 20:22:35

Sorry for the gigantic title, but i have an atom embedded mainboard, this is the model : D525MW

I'm trying to obtain a particular resolution from KMS because i got an old CRT Arcade screen that needs this type of resolution.

When i was using the nuoveau framebuffer it worked fine using this video command for the kernel: video=DVI-I-1:384x288M@51ei (It's a valid modeline for an arcade monitor).
Now KMS picks up the inteldrmfb as framebuffer for my new card but when i try these settings on my VGA port: video=VGA-1:384x288M@51ei, the screens remains black and i got this error message from dmesg:

[ 4.488188] [drm] Initialized drm 1.1.0 20060810
[ 4.740062] [drm] Supports vblank timestamp caching Rev 1 (10.10.2010).
[ 4.740068] [drm] Driver supports precise vblank timestamp query.
[ 5.023872] [drm] initialized overlay support
[ 5.023929] [drm] forcing LVDS-1 connector OFF
[ 5.023938] [drm] forcing VGA-1 connector ON
[ 5.078080] fbcon: inteldrmfb (fb0) is primary device
[ 5.079995] [drm:i9xx_crtc_mode_set] *ERROR* Couldn't find PLL settings for mode!
[ 5.080038] [drm:drm_crtc_helper_set_config] *ERROR* failed to set mode on [CRTC:3]
[ 5.081095] [drm:i9xx_crtc_mode_set] *ERROR* Couldn't find PLL settings for mode!
[ 5.081100] [drm:drm_crtc_helper_set_config] *ERROR* failed to set mode on [CRTC:3]
[ 5.092142] fb0: inteldrmfb frame buffer device
[ 5.092146] drm: registered panic notifier
[ 5.092289] [drm] Initialized i915 1.6.0 20080730 for 0000:00:02.0 on minor 0
[ 6.832232] [drm:i9xx_crtc_mode_set] *ERROR* Couldn't find PLL settings for mode!
[ 6.832241] [drm:drm_crtc_helper_set_config] *ERROR* failed to set mode on [CRTC:3]
[ 6.850054] [drm:i9xx_crtc_mode_set] *ERROR* Couldn't find PLL settings for mode!
[ 6.850064] [drm:drm_crtc_helper_set_config] *ERROR* failed to set mode on [CRTC:3]

Someone has an idea ?

Thanks to all of you for your time.

marcs · 2012-02-20 21:41:47

I've found this piece of code in this source file using egrep (kernel file: /drivers/gpu/drm/i915/intel_display.c):

        /*
         * Returns a set of divisors for the desired target clock with the given
         * refclk, or FALSE.  The returned values represent the clock equation:
         * reflck * (5 * (m1 + 2) + (m2 + 2)) / (n + 2) / p1 / p2.
         */
        limit = intel_limit(crtc, refclk);
        ok = limit->find_pll(limit, crtc, adjusted_mode->clock, refclk, &clock);
        if (!ok) {
                DRM_ERROR("Couldn't find PLL settings for mode!\n");
                return -EINVAL;
        }

I guess that the PLL for my resolution doesn't exist. But i got now another question... What is PLL ?

Gusar · 2012-02-20 22:09:33

Wikipedia to the rescue: http://en.wikipedia.org/wiki/Phase-locked_loop

marcs · 2012-02-21 07:51:06

So it can be also an hardware problem.
The hardware could not support this type of resolution...

That's not good...

Arch Linux

#1 2012-02-20 20:22:35

Custom resolution for intel GMA3150 (Intel NM10 Atom D525)

#2 2012-02-20 21:41:47

Re: Custom resolution for intel GMA3150 (Intel NM10 Atom D525)

#3 2012-02-20 22:09:33

Re: Custom resolution for intel GMA3150 (Intel NM10 Atom D525)

#4 2012-02-21 07:51:06

Re: Custom resolution for intel GMA3150 (Intel NM10 Atom D525)

Board footer