[SOLVED] troubles with 7.4 on intel graphics

Issues related to hardware problems
Posts: 12
Joined: 2016/12/25 08:23:23

[SOLVED] troubles with 7.4 on intel graphics

Postby boblethai » 2017/09/16 07:12:41


I'm back again. I had issues with 7.3 already, it was resolved by TrevorH, thanks again to him, see : https://www.centos.org/forums/viewtopic.php?t=60688

After update to last kernel 3.10.0-693.2.2.el7.x86_64, my X server could not start (as I forced the i915 use in xorg.conf), dmesg tells me:

[ 2.614907] i915: Unknown parameter `preliminary_hw_support'

so I removed the conf file I added (see mentionned post) - xorg.conf and /etc/modprobe.d/i915.conf - , but when I boot (I boot in console mode), I have a nice all black screen.
If I enter my credencials in blind mode, then I can start the X server manually, and I got some video

modinfo confirms the list of parameters for i915 has changed since previous version:

[root@budapest ~]# modinfo -p i915
modeset:Use kernel modesetting [KMS] (0=disable, 1=on, -1=force vga console preference [default]) (int)
panel_ignore_lid:Override lid status (0=autodetect, 1=autodetect disabled [default], -1=force lid closed, -2=force lid open) (int)
semaphores:Use semaphores for inter-ring sync (default: -1 (use per-chip defaults)) (int)
enable_rc6:Enable power-saving render C-state 6. Different stages can be selected via bitmask values (0 = disable; 1 = enable rc6; 2 = enable deep rc6; 4 = enable deepest rc6). For example, 3 would enable rc6 and deep rc6, and 7 would enable everything. default: -1 (use per-chip default) (int)
enable_dc:Enable power-saving display C-states. (-1=auto [default]; 0=disable; 1=up to DC5; 2=up to DC6) (int)
enable_fbc:Enable frame buffer compression for power savings (default: -1 (use per-chip default)) (int)
lvds_channel_mode:Specify LVDS channel mode (0=probe BIOS [default], 1=single-channel, 2=dual-channel) (int)
lvds_use_ssc:Use Spread Spectrum Clock with panels [LVDS/eDP] (default: auto from VBT) (int)
vbt_sdvo_panel_type:Override/Ignore selection of SDVO panel mode in the VBT (-2=ignore, -1=auto [default], index in VBT BIOS table) (int)
reset:Attempt GPU resets (default: true) (bool)
error_capture:Record the GPU state following a hang. This information in /sys/class/drm/card<N>/error is vital for triaging and debugging hangs. (bool)
enable_hangcheck:Periodically check GPU activity for detecting hangs. WARNING: Disabling this can cause system wide hangs. (default: true) (bool)
enable_ppgtt:Override PPGTT usage. (-1=auto [default], 0=disabled, 1=aliasing, 2=full, 3=full with extended address space) (int)
enable_execlists:Override execlists usage. (-1=auto [default], 0=disabled, 1=enabled) (int)
enable_psr:Enable PSR (0=disabled, 1=enabled - link mode chosen per-platform, 2=force link-standby mode, 3=force link-off mode) Default: -1 (use per-chip default) (int)
alpha_support:Enable alpha quality driver support for latest hardware. See also CONFIG_DRM_I915_ALPHA_SUPPORT. (int)
disable_power_well:Disable display power wells when possible (-1=auto [default], 0=power wells always on, 1=power wells disabled when possible) (int)
enable_ips:Enable IPS (default: true) (int)
fastboot:Try to skip unnecessary mode sets at boot time (default: false) (bool)
prefault_disable:Disable page prefaulting for pread/pwrite/reloc (default:false). For developers only. (bool)
load_detect_test:Force-enable the VGA load detect code for testing (default:false). For developers only. (bool)
force_reset_modeset_test:Force a modeset during gpu reset for testing (default:false). For developers only. (bool)
invert_brightness:Invert backlight brightness (-1 force normal, 0 machine defaults, 1 force inversion), please report PCI device ID, subsystem vendor and subsystem device ID to dri-devel@lists.freedesktop.org, if your machine needs it. It will then be included in an upcoming module version. (int)
disable_display:Disable display (default: false) (bool)
enable_cmd_parser:Enable command parsing (1=enabled [default], 0=disabled) (int)
use_mmio_flip:use MMIO flips (-1=never, 0=driver discretion [default], 1=always) (int)
mmio_debug:Enable the MMIO debug code for the first N failures (default: off). This may negatively affect performance. (int)
verbose_state_checks:Enable verbose logs (ie. WARN_ON()) in case of unexpected hw state conditions. (bool)
nuclear_pageflip:Force atomic modeset functionality; asynchronous mode is not yet supported. (default: false). (bool)
edp_vswing:Ignore/Override vswing pre-emph table selection from VBT (0=use value from vbt [default], 1=low power swing(200mV),2=default swing(400mV)) (int)
enable_guc_loading:Enable GuC firmware loading (-1=auto, 0=never [default], 1=if available, 2=required) (int)
enable_guc_submission:Enable GuC submission (-1=auto, 0=never [default], 1=if available, 2=required) (int)
guc_log_level:GuC firmware logging level (-1:disabled (default), 0-3:enabled) (int)
enable_dp_mst:Enable multi-stream transport (MST) for new DisplayPort sinks. (default: true) (bool)
inject_load_failure:Force an error after a number of failure check points (0:disabled (default), N:force failure at the Nth failure check point) (uint)
enable_dpcd_backlight:Enable support for DPCD backlight control (default:false) (bool)
enable_gvt:Enable support for Intel GVT-g graphics virtualization host support(default:false) (bool)

(we can see there there is no preliminary_hw_support parameter anymore)

The display is driven by i915:

[root@budapest ~]# lshw -c display
description: VGA compatible controller
product: 4th Gen Core Processor Integrated Graphics Controller
vendor: Intel Corporation
physical id: 2
bus info: pci@0000:00:02.0
version: 06
width: 64 bits
clock: 33MHz
capabilities: msi pm vga_controller bus_master cap_list rom
configuration: driver=i915 latency=0
resources: irq:30 memory:f7800000-f7bfffff memory:e0000000-efffffff ioport:f000(size=64)

but for X it chooses vesa and not i915 driver (by default, if I have no xorg.conf)

If I force X i915 module use with a file xorg.conf, then it is OK again. I prefer this solution because it seems to be a little bit better when playing videos.

So to sumerise:
- X video works with both vesa and i915
- console is black. As I do not use always my laptop in graphics mode, it is an issue ...

Thanks in advance if you have any suggestion.

Last edited by boblethai on 2017/09/22 11:56:39, edited 1 time in total.

Posts: 12
Joined: 2016/12/25 08:23:23

Re: troubles with 7.4 on intel graphics

Postby boblethai » 2017/09/22 11:55:43

OK, finally found it, in https://wiki.archlinux.org/index.php/kernel_mode_setting . I had a vga=0x37d in the grub line. If I remove it, console mode and graphic mode are both OK.

I try to set the topic SOLVED, if I find a way ...