linux_dsm_epyc7002/drivers/gpu/drm
Keith Packard f01eca2e52 drm/i915: Correct eDP panel power sequencing delay computations
Store the panel power sequencing delays in the dp private structure,
rather than the global device structure. Who knows, maybe we'll get
more than one eDP device in the future.

From the eDP spec, we need the following numbers:

 T1 + T3	Power on to Aux Channel operation (panel_power_up_delay)

		This marks how long it takes the panel to boot up and
		get ready to receive aux channel communications.

 T8		Video signal to backlight on (backlight_on_delay)

		Once a valid video signal is being sent to the device,
		it can take a while before the panel is actuall
		showing useful data. This delay allows the panel
		to get something reasonable up before the backlight
		is turned on.

 T9		Backlight off to video off (backlight_off_delay)

		Turning the backlight off can take a moment, so
		this delay makes sure there is still valid video
		data on the screen.

 T10		Video off to power off (panel_power_down_delay)

		Presumably this delay allows the panel to perform
		an orderly shutdown of the display.

 T11 + T12	Power off to power on (panel_power_cycle_delay)

		So, once you turn the panel off, you have to wait a
		while before you can turn it back on. This delay is
		usually the longest in the entire sequence.

Neither the VBIOS source code nor the hardware documentation has a
clear mapping between the delay values they provide and those required
by the eDP spec. The VBIOS code actually uses two different labels for
the delay values in the five words of the relevant VBT table.

**** MORE LATER ***

Look at both the current hardware register settings and the VBT
specified panel power sequencing timings. Use the maximum of the two
delays, to make sure things work reliably. If there is no VBT data,
then those values will be initialized to zero, so we'll just use the
values as programmed in the hardware. Note that the BIOS just fetches
delays from the VBT table to place in the hardware registers, so we
should get the same values from both places, except for rounding.

VBT doesn't provide any values for T1 or T2, so we'll always just use
the hardware value for that.

The panel power up delay is thus T1 + T2 + T3, which should be
sufficient in all cases.

The panel power down delay is T1 + T2 + T12, using T1+T2 as a proxy
for T11, which isn't available anywhere.

For the backlight delays, the eDP spec says T6 + T8 is the delay from the
end of link training to backlight on and T9 is the delay from
backlight off until video off. The hardware provides a 'backlight on'
delay, which I'm taking to be T6 + T8 while the VBT provides something
called 'T7', which I'm assuming is s

On the macbook air I'm testing with, this yields a power-up delay of
over 200ms and a power-down delay of over 600ms. It all works now, but
we're frobbing these power controls several times during mode setting,
making the whole process take an awfully long time.

Signed-off-by: Keith Packard <keithp@keithp.com>
2011-10-06 08:37:15 -07:00
..
i2c
i810 drm: rework PCI/platform driver interface. 2011-02-07 13:09:36 +10:00
i915 drm/i915: Correct eDP panel power sequencing delay computations 2011-10-06 08:37:15 -07:00
mga alpha, drm: Remove obsolete Alpha support in MGA DRM code 2011-06-14 09:32:56 +10:00
nouveau drm/nv04/crtc: Bail out if FB is not bound to crtc 2011-09-09 17:24:21 +10:00
r128 drm: rework PCI/platform driver interface. 2011-02-07 13:09:36 +10:00
radeon drm/radeon/kms: fix DP detect and EDID fetch for DP bridges 2011-09-06 11:46:36 +01:00
savage savage: remove unnecessary if statement 2011-06-14 09:29:12 +10:00
sis treewide: fix potentially dangerous trailing ';' in #defined values/expressions 2011-07-21 14:10:00 +02:00
tdfx drm: rework PCI/platform driver interface. 2011-02-07 13:09:36 +10:00
ttm drm/ttm: ensure ttm for new node is bound before calling move_notify() 2011-08-23 09:38:30 +01:00
via drm: rework PCI/platform driver interface. 2011-02-07 13:09:36 +10:00
vmwgfx drivers: use kzalloc/kcalloc instead of 'kmalloc+memset', where possible 2011-07-25 20:57:13 -07:00
ati_pcigart.c
drm_agpsupport.c
drm_auth.c
drm_buffer.c
drm_bufs.c drm: Compare only lower 32 bits of framebuffer map offsets 2011-06-14 11:09:54 +10:00
drm_cache.c
drm_context.c
drm_crtc_helper.c drm: bpp and depth changes require full mode sets 2011-07-07 13:20:49 -07:00
drm_crtc.c drm: Fix the number of connector and encoder to cleanup functions 2011-08-29 11:47:35 +01:00
drm_debugfs.c drm/debugfs: Initialise empty variable 2011-08-04 14:38:52 +01:00
drm_dma.c
drm_dp_i2c_helper.c
drm_drv.c drm/core: add ioctl to query device/driver capabilities 2011-03-04 14:47:30 +10:00
drm_edid_modes.h drm: Mark constant arrays of drm_display_mode const 2011-02-23 11:13:11 +10:00
drm_edid.c drm: Separate EDID Header Check from EDID Block Check 2011-08-04 14:39:35 +01:00
drm_encoder_slave.c
drm_fb_helper.c drm: Remove duplicate "return" statement 2011-09-09 09:11:44 +01:00
drm_fops.c drm/switcheroo: track state of switch in drivers. 2011-01-05 13:45:30 +10:00
drm_gem.c drm/gem: add support for private objects 2011-07-25 12:07:15 +01:00
drm_global.c
drm_hashtab.c drm: Remove unused members from struct drm_open_hash 2011-02-23 11:16:40 +10:00
drm_info.c Merge remote branch 'intel/drm-intel-next' of ../drm-next into drm-core-next 2011-03-14 14:15:13 +10:00
drm_ioc32.c drivers/gpu/drm: use printk_ratelimited instead of printk_ratelimit 2011-06-16 16:32:15 +10:00
drm_ioctl.c drm/vblank: update recently added vbl interface to be more future proof. 2011-03-24 21:28:46 +10:00
drm_irq.c drm: Add NULL check about irq functions 2011-08-04 14:39:21 +01:00
drm_lock.c
drm_memory.c
drm_mm.c drm: mm: fix debug output 2011-05-09 09:14:45 +10:00
drm_modes.c DRM: clean up and document parsing of video= parameter 2011-07-25 12:02:26 +01:00
drm_pci.c drm: populate irq_by_busid-member for pci 2011-06-16 16:26:45 +10:00
drm_platform.c drm: platform multi-device support 2011-07-15 06:52:58 +01:00
drm_proc.c
drm_scatter.c drivers: use kzalloc/kcalloc instead of 'kmalloc+memset', where possible 2011-07-25 20:57:13 -07:00
drm_sman.c GPU DRM: Remove unnecessary casts of void ptr returning alloc function return values 2011-01-19 15:24:49 +01:00
drm_stub.c drm: Create and use drm_err 2011-04-28 14:53:02 +10:00
drm_sysfs.c drm: Hold the mode mutex whilst probing for sysfs status 2011-03-16 11:23:04 +10:00
drm_trace_points.c
drm_trace.h
drm_usb.c drm: add usb framework 2011-02-07 13:09:42 +10:00
drm_vm.c alpha/drm: Cleanup Alpha support in DRM generic code 2011-06-14 09:31:37 +10:00
Kconfig drm: select FRAMEBUFFER_CONSOLE_PRIMARY if we have FRAMEBUFFER_CONSOLE 2011-04-27 16:54:06 +10:00
Makefile drm: add usb framework 2011-02-07 13:09:42 +10:00
README.drm

************************************************************
* For the very latest on DRI development, please see:      *
*     http://dri.freedesktop.org/                          *
************************************************************

The Direct Rendering Manager (drm) is a device-independent kernel-level
device driver that provides support for the XFree86 Direct Rendering
Infrastructure (DRI).

The DRM supports the Direct Rendering Infrastructure (DRI) in four major
ways:

    1. The DRM provides synchronized access to the graphics hardware via
       the use of an optimized two-tiered lock.

    2. The DRM enforces the DRI security policy for access to the graphics
       hardware by only allowing authenticated X11 clients access to
       restricted regions of memory.

    3. The DRM provides a generic DMA engine, complete with multiple
       queues and the ability to detect the need for an OpenGL context
       switch.

    4. The DRM is extensible via the use of small device-specific modules
       that rely extensively on the API exported by the DRM module.


Documentation on the DRI is available from:
    http://dri.freedesktop.org/wiki/Documentation
    http://sourceforge.net/project/showfiles.php?group_id=387
    http://dri.sourceforge.net/doc/

For specific information about kernel-level support, see:

    The Direct Rendering Manager, Kernel Support for the Direct Rendering
    Infrastructure
    http://dri.sourceforge.net/doc/drm_low_level.html

    Hardware Locking for the Direct Rendering Infrastructure
    http://dri.sourceforge.net/doc/hardware_locking_low_level.html

    A Security Analysis of the Direct Rendering Infrastructure
    http://dri.sourceforge.net/doc/security_low_level.html