1.\" 2.\" Copyright (c) 2015 The DragonFly Project. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in 12.\" the documentation and/or other materials provided with the 13.\" distribution. 14.\" 3. Neither the name of The DragonFly Project nor the names of its 15.\" contributors may be used to endorse or promote products derived 16.\" from this software without specific, prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20.\" LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 21.\" FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 22.\" COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 23.\" INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 24.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 25.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 26.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 27.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 28.\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.Dd October 9, 2019 32.Dt I915 4 33.Os 34.Sh NAME 35.Nm i915 36.Nd Driver for Intel i915 family integrated graphics chipsets 37.Sh DESCRIPTION 38The 39.Nm 40driver provides support for integrated graphics chips by Intel. 41Please refer the 42.Sx Loader Tunables 43section in 44.Xr syscons 4 45for more information about how to make the console work with 46.Nm . 47.Sh LOADER TUNABLES 48Tunables can be set at the 49.Xr loader 8 50prompt before booting the kernel or stored in 51.Xr loader.conf 5 . 52.Bl -tag -width "xxxxxx" 53.It Va drm.i915.disable_aux_irq 54When non-zero, disable interrupt usage for DisplayPort AUX channel. 55This option doesn't affect GPU models older than Generation 5 (Ironlake). 56Can be used as a workaround in cases where DisplayPort panel 57initialization is unreliable, which often leaves a blank screen after the 58.Nm 59module was loaded. 60.br 611 = don't use AUX IRQ, 0 = auto (default). 62.It Va drm.i915.enable_psr 63Enable PSR (panel self refresh), only relevant for Haswell and Broadwell 64CPUs. 651 = enable, 0 = disable (default). 66To maximize PSR usage, it can be beneficial to set 67.Va hw.dri.vblank_offdelay 68(see 69.Xr drm 4 ) 70to a sufficiently low value (or 71.Li -1 ) , 72to minimize vblank interrupt activity. 73.It Va drm.i915.enable_execlists 74Override execlists usage on Broadwell IGPs (no effect on other IGP models). 75Disabling execlists reverts to legacy ringbuffer mode. 76-1 = auto (default), 0 = disable, 1 = enable 77.El 78.Sh SYSCTL VARIABLES 79If display backlight level can be controlled by the GPU (which is often 80the case in notebooks), the sysctl 81.Va hw.backlight_level 82can be used to adjust the backlight level. 83Permitted values are from 0 to the value of 84.Va hw.backlight_max . 85.Sh SEE ALSO 86.Xr drm 4 , 87.Xr syscons 4 88.Sh HISTORY 89The 90.Nm 91driver was first available for Linux. 92