# Resolution reduced on kernel upgrade w. Haswell graphics

## mounty1

Hello, I recently upgraded my kernel from 4.7.4 to 4.10.11 on an Intel NUC with the following graphics:

```
...

00:02.0 VGA compatible controller: Intel Corporation Haswell-ULT Integrated Graphics Controller (rev 09) (prog-if 00 [VGA controller])

        Subsystem: Intel Corporation Haswell-ULT Integrated Graphics Controller

        Flags: bus master, fast devsel, latency 0, IRQ 43

        Memory at f7800000 (64-bit, non-prefetchable) [size=4M]

        Memory at e0000000 (64-bit, prefetchable) [size=256M]

        I/O ports at f000 [size=64]

        [virtual] Expansion ROM at 000c0000 [disabled] [size=128K]

        Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-

        Capabilities: [d0] Power Management version 2

        Capabilities: [a4] PCI Advanced Features

        Kernel driver in use: i915

        Kernel modules: i915
```

As you can see, the i915 driver is loaded, as expected.  I performed the upgrade by copying the kernel .config then running make oldconfig.  There are too many customisations to make it practical to start again with a fresh .config.  Kernel .config here.

After the upgrade, the resolution which with the 4.7.4 kernel was 2560x1600, was limited to 1920x1200.  There are no obvious error messages or warning in either dmesg or /var/log/Xorg.0.log.  In particular, there are no ABI major version mismatches reported in /var/log/Xorg.0.log.  Following these instructions, I tried the following, in a terminal session:

```
mounty@kendall ~ $ sudo -i

Password: 

kendall ~ # cvt 2560 1600

# 2560x1600 59.99 Hz (CVT 4.10MA) hsync: 99.46 kHz; pclk: 348.50 MHz

Modeline "2560x1600_60.00"  348.50  2560 2760 3032 3504  1600 1603 1609 1658 -hsync +vsync

kendall ~ # xrandr --newmode "2560x1600_60.00"  348.50  2560 2760 3032 3504  1600 1603 1609 1658 -hsync +vsync

kendall ~ # xrandr --addmode HDMI1 "2560x1600_60.00"

kendall ~ # xrandr --output HDMI1 --mode 2560x1600_60.00 --verbose

screen 0: 2560x1600 676x422 mm  96.15dpi

crtc 0: 2560x1600_60.00  59.99 +0+0 "HDMI1"

xrandr: Configure crtc 0 failed

crtc 0: disable

crtc 1: disable

crtc 2: disable

crtc 3: disable

screen 0: revert

crtc 0: revert

crtc 1: revert

crtc 2: revert

crtc 3: revert

kendall ~ #
```

and although the screen went blank for a moment, the resolution was not increased from 1920x1200.

Previously, I'd emerge -q1 xorg-drivers xorg-server xf86-video-driver which did clear an ABI major version mismatch but hasn't fixed the problem.

How to get the higher resolution back?  I am stuck on the previous kernel for now.

[Later] I tried to bisect kernels to see where the problem arises but the oldest I can find beyond 4.7.4 is 4.9.0 but that has the same fault as 4.10.11.  I really need to go back to 4.7[5-9] or 4.8 but don't have the source available.  I diffed dmesg from 4.7.0 and 4.9.0 but can't see anything suspicious.

----------

## Jaglover

Have you tried with modesetting Xorg driver?

----------

## mounty1

As indicated in my OP, I've tried setting the mode via xrandr and it doesn't work, so why would the modesetting X driver?

The problem is in KMS, because with kernel 4.9.0ff, the `text' console font is somewhat larger than the 4.7.4 font.

----------

## mounty1

here

----------

