[GitHub/mt8127/android_kernel_alcatel_ttab.git] / Documentation / power / video.txt


		Video issues with S3 resume
		~~~~~~~~~~~~~~~~~~~~~~~~~~~
		  2003-2006, Pavel Machek

During S3 resume, hardware needs to be reinitialized. For most
devices, this is easy, and kernel driver knows how to do
it. Unfortunately there's one exception: video card. Those are usually
initialized by BIOS, and kernel does not have enough information to
boot video card. (Kernel usually does not even contain video card
driver -- vesafb and vgacon are widely used).

This is not problem for swsusp, because during swsusp resume, BIOS is
run normally so video card is normally initialized. It should not be
problem for S1 standby, because hardware should retain its state over
that.

We either have to run video BIOS during early resume, or interpret it
using vbetool later, or maybe nothing is necessary on particular
system because video state is preserved. Unfortunately different
methods work on different systems, and no known method suits all of
them.

Userland application called s2ram has been developed; it contains long
whitelist of systems, and automatically selects working method for a
given system. It can be downloaded from CVS at
www.sf.net/projects/suspend . If you get a system that is not in the
whitelist, please try to find a working solution, and submit whitelist
entry so that work does not need to be repeated.

Currently, VBE_SAVE method (6 below) works on most
systems. Unfortunately, vbetool only runs after userland is resumed,
so it makes debugging of early resume problems
hard/impossible. Methods that do not rely on userland are preferable.

Details
~~~~~~~

There are a few types of systems where video works after S3 resume:

(1) systems where video state is preserved over S3.

(2) systems where it is possible to call the video BIOS during S3
  resume. Unfortunately, it is not correct to call the video BIOS at
  that point, but it happens to work on some machines. Use
  acpi_sleep=s3_bios.

(3) systems that initialize video card into vga text mode and where
  the BIOS works well enough to be able to set video mode. Use
  acpi_sleep=s3_mode on these.

(4) on some systems s3_bios kicks video into text mode, and
  acpi_sleep=s3_bios,s3_mode is needed.

(5) radeon systems, where X can soft-boot your video card. You'll need
  a new enough X, and a plain text console (no vesafb or radeonfb). See
  http://www.doesi.gmxhome.de/linux/tm800s3/s3.html for more information.
  Alternatively, you should use vbetool (6) instead.

(6) other radeon systems, where vbetool is enough to bring system back
  to life. It needs text console to be working. Do vbetool vbestate
  save > /tmp/delme; echo 3 > /proc/acpi/sleep; vbetool post; vbetool
  vbestate restore < /tmp/delme; setfont <whatever>, and your video
  should work.

(7) on some systems, it is possible to boot most of kernel, and then
  POSTing bios works. Ole Rohne has patch to do just that at
  http://dev.gentoo.org/~marineam/patch-radeonfb-2.6.11-rc2-mm2.

(8) on some systems, you can use the video_post utility and or 
  do echo 3 > /sys/power/state  && /usr/sbin/video_post - which will 
  initialize the display in console mode. If you are in X, you can switch
  to a virtual terminal and back to X using  CTRL+ALT+F1 - CTRL+ALT+F7 to get
  the display working in graphical mode again.

Now, if you pass acpi_sleep=something, and it does not work with your
bios, you'll get a hard crash during resume. Be careful. Also it is
safest to do your experiments with plain old VGA console. The vesafb
and radeonfb (etc) drivers have a tendency to crash the machine during
resume.

You may have a system where none of above works. At that point you
either invent another ugly hack that works, or write proper driver for
your video card (good luck getting docs :-(). Maybe suspending from X
(proper X, knowing your hardware, not XF68_FBcon) might have better
chance of working.

Table of known working notebooks:

Model                           hack (or "how to do it")
------------------------------------------------------------------------------
Acer Aspire 1406LC		ole's late BIOS init (7), turn off DRI
Acer TM 230			s3_bios (2)
Acer TM 242FX			vbetool (6)
Acer TM C110			video_post (8)
Acer TM C300                    vga=normal (only suspend on console, not in X), vbetool (6) or video_post (8)
Acer TM 4052LCi		        s3_bios (2)
Acer TM 636Lci			s3_bios,s3_mode (4)
Acer TM 650 (Radeon M7)		vga=normal plus boot-radeon (5) gets text console back
Acer TM 660			??? (*)
Acer TM 800			vga=normal, X patches, see webpage (5) or vbetool (6)
Acer TM 803			vga=normal, X patches, see webpage (5) or vbetool (6)
Acer TM 803LCi			vga=normal, vbetool (6)
Arima W730a			vbetool needed (6)
Asus L2400D                     s3_mode (3)(***) (S1 also works OK)
Asus L3350M (SiS 740)           (6)
Asus L3800C (Radeon M7)		s3_bios (2) (S1 also works OK)
Asus M6887Ne			vga=normal, s3_bios (2), use radeon driver instead of fglrx in x.org
Athlon64 desktop prototype	s3_bios (2)
Compal CL-50			??? (*)
Compaq Armada E500 - P3-700     none (1) (S1 also works OK)
Compaq Evo N620c		vga=normal, s3_bios (2)
Dell 600m, ATI R250 Lf		none (1), but needs xorg-x11-6.8.1.902-1
Dell D600, ATI RV250            vga=normal and X, or try vbestate (6)
Dell D610			vga=normal and X (possibly vbestate (6) too, but not tested)
Dell Inspiron 4000		??? (*)
Dell Inspiron 500m		??? (*)
Dell Inspiron 510m		???
Dell Inspiron 5150		vbetool needed (6)
Dell Inspiron 600m		??? (*)
Dell Inspiron 8200		??? (*)
Dell Inspiron 8500		??? (*)
Dell Inspiron 8600		??? (*)
eMachines athlon64 machines	vbetool needed (6) (someone please get me model #s)
HP NC6000			s3_bios, may not use radeonfb (2); or vbetool (6)
HP NX7000			??? (*)
HP Pavilion ZD7000		vbetool post needed, need open-source nv driver for X
HP Omnibook XE3	athlon version	none (1)
HP Omnibook XE3GC		none (1), video is S3 Savage/IX-MV
HP Omnibook XE3L-GF		vbetool (6)
HP Omnibook 5150		none (1), (S1 also works OK)
IBM TP T20, model 2647-44G	none (1), video is S3 Inc. 86C270-294 Savage/IX-MV, vesafb gets "interesting" but X work.
IBM TP A31 / Type 2652-M5G      s3_mode (3) [works ok with BIOS 1.04 2002-08-23, but not at all with BIOS 1.11 2004-11-05 :-(]
IBM TP R32 / Type 2658-MMG      none (1)
IBM TP R40 2722B3G		??? (*)
IBM TP R50p / Type 1832-22U     s3_bios (2)
IBM TP R51			none (1)
IBM TP T30	236681A		??? (*)
IBM TP T40 / Type 2373-MU4      none (1)
IBM TP T40p			none (1)
IBM TP R40p			s3_bios (2)
IBM TP T41p			s3_bios (2), switch to X after resume
IBM TP T42			s3_bios (2)
IBM ThinkPad T42p (2373-GTG)	s3_bios (2)
IBM TP X20			??? (*)
IBM TP X30			s3_bios, s3_mode (4)
IBM TP X31 / Type 2672-XXH      none (1), use radeontool (http://fdd.com/software/radeon/) to turn off backlight.
IBM TP X32			none (1), but backlight is on and video is trashed after long suspend. s3_bios,s3_mode (4) works too. Perhaps that gets better results?
IBM Thinkpad X40 Type 2371-7JG  s3_bios,s3_mode (4)
IBM TP 600e			none(1), but a switch to console and back to X is needed
Medion MD4220			??? (*)
Samsung P35			vbetool needed (6)
Sharp PC-AR10 (ATI rage)	none (1), backlight does not switch off
Sony Vaio PCG-C1VRX/K		s3_bios (2)
Sony Vaio PCG-F403		??? (*)
Sony Vaio PCG-GRT995MP		none (1), works with 'nv' X driver
Sony Vaio PCG-GR7/K		none (1), but needs radeonfb, use radeontool (http://fdd.com/software/radeon/) to turn off backlight.
Sony Vaio PCG-N505SN		??? (*)
Sony Vaio vgn-s260		X or boot-radeon can init it (5)
Sony Vaio vgn-S580BH		vga=normal, but suspend from X. Console will be blank unless you return to X.
Sony Vaio vgn-FS115B		s3_bios (2),s3_mode (4)
Toshiba Libretto L5		none (1)
Toshiba Libretto 100CT/110CT    vbetool (6)
Toshiba Portege 3020CT		s3_mode (3)
Toshiba Satellite 4030CDT	s3_mode (3) (S1 also works OK)
Toshiba Satellite 4080XCDT      s3_mode (3) (S1 also works OK)
Toshiba Satellite 4090XCDT      ??? (*)
Toshiba Satellite P10-554       s3_bios,s3_mode (4)(****)
Toshiba M30                     (2) xor X with nvidia driver using internal AGP
Uniwill 244IIO			??? (*)

Known working desktop systems
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Mainboard	    Graphics card                 hack (or "how to do it")
------------------------------------------------------------------------------
Asus A7V8X	    nVidia RIVA TNT2 model 64	  s3_bios,s3_mode (4)


(*) from https://wiki.ubuntu.com/HoaryPMResults, not sure
    which options to use. If you know, please tell me.

(***) To be tested with a newer kernel.

(****) Not with SMP kernel, UP only.
Commit	Line	Data
1da177e4 LT	1
	2	Video issues with S3 resume
	3	~~~~~~~~~~~~~~~~~~~~~~~~~~~
543cc27d	4	2003-2006, Pavel Machek
1da177e4 LT	5
	6	During S3 resume, hardware needs to be reinitialized. For most
	7	devices, this is easy, and kernel driver knows how to do
	8	it. Unfortunately there's one exception: video card. Those are usually
	9	initialized by BIOS, and kernel does not have enough information to
	10	boot video card. (Kernel usually does not even contain video card
	11	driver -- vesafb and vgacon are widely used).
	12
	13	This is not problem for swsusp, because during swsusp resume, BIOS is
36fabc24 PM	14	run normally so video card is normally initialized. It should not be
	15	problem for S1 standby, because hardware should retain its state over
	16	that.
1da177e4	17
543cc27d	18	We either have to run video BIOS during early resume, or interpret it
992caacf	19	using vbetool later, or maybe nothing is necessary on particular
543cc27d PM	20	system because video state is preserved. Unfortunately different
	21	methods work on different systems, and no known method suits all of
	22	them.
	23
	24	Userland application called s2ram has been developed; it contains long
	25	whitelist of systems, and automatically selects working method for a
	26	given system. It can be downloaded from CVS at
	27	www.sf.net/projects/suspend . If you get a system that is not in the
	28	whitelist, please try to find a working solution, and submit whitelist
	29	entry so that work does not need to be repeated.
	30
	31	Currently, VBE_SAVE method (6 below) works on most
	32	systems. Unfortunately, vbetool only runs after userland is resumed,
	33	so it makes debugging of early resume problems
	34	hard/impossible. Methods that do not rely on userland are preferable.
	35
	36	Details
	37	~~~~~~~
	38
1da177e4 LT	39	There are a few types of systems where video works after S3 resume:
	40
	41	(1) systems where video state is preserved over S3.
	42
	43	(2) systems where it is possible to call the video BIOS during S3
	44	resume. Unfortunately, it is not correct to call the video BIOS at
	45	that point, but it happens to work on some machines. Use
	46	acpi_sleep=s3_bios.
	47
	48	(3) systems that initialize video card into vga text mode and where
	49	the BIOS works well enough to be able to set video mode. Use
	50	acpi_sleep=s3_mode on these.
	51
	52	(4) on some systems s3_bios kicks video into text mode, and
	53	acpi_sleep=s3_bios,s3_mode is needed.
	54
	55	(5) radeon systems, where X can soft-boot your video card. You'll need
a4ffad5b PM	56	a new enough X, and a plain text console (no vesafb or radeonfb). See
	57	http://www.doesi.gmxhome.de/linux/tm800s3/s3.html for more information.
	58	Alternatively, you should use vbetool (6) instead.
1da177e4 LT	59
	60	(6) other radeon systems, where vbetool is enough to bring system back
	61	to life. It needs text console to be working. Do vbetool vbestate
	62	save > /tmp/delme; echo 3 > /proc/acpi/sleep; vbetool post; vbetool
	63	vbestate restore < /tmp/delme; setfont <whatever>, and your video
	64	should work.
	65
	66	(7) on some systems, it is possible to boot most of kernel, and then
	67	POSTing bios works. Ole Rohne has patch to do just that at
	68	http://dev.gentoo.org/~marineam/patch-radeonfb-2.6.11-rc2-mm2.
	69
0ea6e611 JM	70	(8) on some systems, you can use the video_post utility and or
	71	do echo 3 > /sys/power/state && /usr/sbin/video_post - which will
	72	initialize the display in console mode. If you are in X, you can switch
	73	to a virtual terminal and back to X using CTRL+ALT+F1 - CTRL+ALT+F7 to get
	74	the display working in graphical mode again.
7e958883	75
1da177e4 LT	76	Now, if you pass acpi_sleep=something, and it does not work with your
	77	bios, you'll get a hard crash during resume. Be careful. Also it is
	78	safest to do your experiments with plain old VGA console. The vesafb
	79	and radeonfb (etc) drivers have a tendency to crash the machine during
	80	resume.
	81
	82	You may have a system where none of above works. At that point you
	83	either invent another ugly hack that works, or write proper driver for
	84	your video card (good luck getting docs :-(). Maybe suspending from X
	85	(proper X, knowing your hardware, not XF68_FBcon) might have better
	86	chance of working.
	87
36fabc24	88	Table of known working notebooks:
1da177e4 LT	89
	90	Model hack (or "how to do it")
	91	------------------------------------------------------------------------------
	92	Acer Aspire 1406LC ole's late BIOS init (7), turn off DRI
e084dbd3	93	Acer TM 230 s3_bios (2)
1da177e4	94	Acer TM 242FX vbetool (6)
7e958883 PM	95	Acer TM C110 video_post (8)
7e958883 PM	96	Acer TM C300 vga=normal (only suspend on console, not in X), vbetool (6) or video_post (8)
1da177e4	97	Acer TM 4052LCi s3_bios (2)
36fabc24	98	Acer TM 636Lci s3_bios,s3_mode (4)
1da177e4 LT	99	Acer TM 650 (Radeon M7) vga=normal plus boot-radeon (5) gets text console back
	100	Acer TM 660 ??? (*)
	101	Acer TM 800 vga=normal, X patches, see webpage (5) or vbetool (6)
	102	Acer TM 803 vga=normal, X patches, see webpage (5) or vbetool (6)
	103	Acer TM 803LCi vga=normal, vbetool (6)
	104	Arima W730a vbetool needed (6)
	105	Asus L2400D s3_mode (3)(***) (S1 also works OK)
a4ffad5b	106	Asus L3350M (SiS 740) (6)
1da177e4	107	Asus L3800C (Radeon M7) s3_bios (2) (S1 also works OK)
a4ffad5b	108	Asus M6887Ne vga=normal, s3_bios (2), use radeon driver instead of fglrx in x.org
1da177e4 LT	109	Athlon64 desktop prototype s3_bios (2)
	110	Compal CL-50 ??? (*)
	111	Compaq Armada E500 - P3-700 none (1) (S1 also works OK)
	112	Compaq Evo N620c vga=normal, s3_bios (2)
	113	Dell 600m, ATI R250 Lf none (1), but needs xorg-x11-6.8.1.902-1
	114	Dell D600, ATI RV250 vga=normal and X, or try vbestate (6)
2a962065	115	Dell D610 vga=normal and X (possibly vbestate (6) too, but not tested)
1da177e4 LT	116	Dell Inspiron 4000 ??? (*)
1da177e4 LT	117	Dell Inspiron 500m ??? (*)
2a962065	118	Dell Inspiron 510m ???
e084dbd3	119	Dell Inspiron 5150 vbetool needed (6)
1da177e4 LT	120	Dell Inspiron 600m ??? (*)
	121	Dell Inspiron 8200 ??? (*)
	122	Dell Inspiron 8500 ??? (*)
	123	Dell Inspiron 8600 ??? (*)
	124	eMachines athlon64 machines vbetool needed (6) (someone please get me model #s)
	125	HP NC6000 s3_bios, may not use radeonfb (2); or vbetool (6)
	126	HP NX7000 ??? (*)
	127	HP Pavilion ZD7000 vbetool post needed, need open-source nv driver for X
	128	HP Omnibook XE3 athlon version none (1)
	129	HP Omnibook XE3GC none (1), video is S3 Savage/IX-MV
e084dbd3	130	HP Omnibook XE3L-GF vbetool (6)
543cc27d	131	HP Omnibook 5150 none (1), (S1 also works OK)
1da177e4 LT	132	IBM TP T20, model 2647-44G none (1), video is S3 Inc. 86C270-294 Savage/IX-MV, vesafb gets "interesting" but X work.
	133	IBM TP A31 / Type 2652-M5G s3_mode (3) [works ok with BIOS 1.04 2002-08-23, but not at all with BIOS 1.11 2004-11-05 :-(]
	134	IBM TP R32 / Type 2658-MMG none (1)
	135	IBM TP R40 2722B3G ??? (*)
	136	IBM TP R50p / Type 1832-22U s3_bios (2)
a4ffad5b	137	IBM TP R51 none (1)
1da177e4 LT	138	IBM TP T30 236681A ??? (*)
	139	IBM TP T40 / Type 2373-MU4 none (1)
	140	IBM TP T40p none (1)
	141	IBM TP R40p s3_bios (2)
	142	IBM TP T41p s3_bios (2), switch to X after resume
a4ffad5b	143	IBM TP T42 s3_bios (2)
1da177e4 LT	144	IBM ThinkPad T42p (2373-GTG) s3_bios (2)
1da177e4 LT	145	IBM TP X20 ??? (*)
9587c4bf	146	IBM TP X30 s3_bios, s3_mode (4)
1da177e4	147	IBM TP X31 / Type 2672-XXH none (1), use radeontool (http://fdd.com/software/radeon/) to turn off backlight.
543cc27d	148	IBM TP X32 none (1), but backlight is on and video is trashed after long suspend. s3_bios,s3_mode (4) works too. Perhaps that gets better results?
1da177e4	149	IBM Thinkpad X40 Type 2371-7JG s3_bios,s3_mode (4)
543cc27d	150	IBM TP 600e none(1), but a switch to console and back to X is needed
1da177e4 LT	151	Medion MD4220 ??? (*)
1da177e4 LT	152	Samsung P35 vbetool needed (6)
543cc27d	153	Sharp PC-AR10 (ATI rage) none (1), backlight does not switch off
374a6cf2	154	Sony Vaio PCG-C1VRX/K s3_bios (2)
1da177e4	155	Sony Vaio PCG-F403 ??? (*)
543cc27d PM	156	Sony Vaio PCG-GRT995MP none (1), works with 'nv' X driver
543cc27d PM	157	Sony Vaio PCG-GR7/K none (1), but needs radeonfb, use radeontool (http://fdd.com/software/radeon/) to turn off backlight.
1da177e4 LT	158	Sony Vaio PCG-N505SN ??? (*)
1da177e4 LT	159	Sony Vaio vgn-s260 X or boot-radeon can init it (5)
543cc27d PM	160	Sony Vaio vgn-S580BH vga=normal, but suspend from X. Console will be blank unless you return to X.
543cc27d PM	161	Sony Vaio vgn-FS115B s3_bios (2),s3_mode (4)
1da177e4	162	Toshiba Libretto L5 none (1)
e084dbd3	163	Toshiba Libretto 100CT/110CT vbetool (6)
543cc27d PM	164	Toshiba Portege 3020CT s3_mode (3)
	165	Toshiba Satellite 4030CDT s3_mode (3) (S1 also works OK)
	166	Toshiba Satellite 4080XCDT s3_mode (3) (S1 also works OK)
1da177e4 LT	167	Toshiba Satellite 4090XCDT ??? (*)
1da177e4 LT	168	Toshiba Satellite P10-554 s3_bios,s3_mode (4)(****)
2a962065	169	Toshiba M30 (2) xor X with nvidia driver using internal AGP
1da177e4 LT	170	Uniwill 244IIO ??? (*)
1da177e4 LT	171
36fabc24 PM	172	Known working desktop systems
	173	~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	174
	175	Mainboard Graphics card hack (or "how to do it")
	176	------------------------------------------------------------------------------
	177	Asus A7V8X nVidia RIVA TNT2 model 64 s3_bios,s3_mode (4)
	178
1da177e4	179
0ea6e611	180	(*) from https://wiki.ubuntu.com/HoaryPMResults, not sure
1da177e4 LT	181	which options to use. If you know, please tell me.
	182
	183	(***) To be tested with a newer kernel.
	184
	185	(****) Not with SMP kernel, UP only.