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diff --git a/docs/future/old.md b/docs/future/old.md new file mode 100644 index 00000000..88c6cc1b --- /dev/null +++ b/docs/future/old.md @@ -0,0 +1,279 @@ +<div class="section"> + +Development notes (old/obsolete notes) {#pagetop} +====================================== + +For current notes, see [](./). + +These are old (obsolete) notes that mare kept because they might become +useful again in the future. + +</div> + +<div class="section"> + +Table of contents +================= + +- [X60 native graphics initialization (backlight + controls)](#x60_native_notes) +- [T60 native graphics initialization (backlight + controls)](#t60_native_notes) +- [i945: 3D fix (based on 5927) for kernel 3.12+ on + 5320](#5320_kernel312fix) +- [i945/x60: coreboot 5927 testing (3D fix for kernel 3.12+ on replay + code)](#x60_cb5927_testing) + +</div> + +<div class="section"> + +X60 native graphics initialization (with backlight controls) {#x60_native_notes} +============================================================ + +**This is now obsolete. A better way was found (included in libreboot): +<http://review.coreboot.org/#/c/6731/>** + +***Also check [\#5320\_kernel312fix](#5320_kernel312fix) (to fix 3D on +kernel 3.12/higher)*** + +**The fix below was done on 5320/6 (from review.coreboot.org) but should +work just fine on later versions of 5320.** + +Native gpu init + backlight controls! (Fn keys). Also confirmed on X60 +Tablet (1024x768) and X60 Tablet (1400x1050) + +**Add backlight controls:** in *src/mainboard/lenovo/x60/devicetree.cb*, +change **gpu\_backlight** to **0x879F879E** + +That\'s all! **This has also been backported into libreboot 5th release +(line 1233 in src/mainboard/lenovo/x60/i915io.c)**. GNUtoo (Denis +Carikli) told me about the register **BLC\_PWM\_CTL** and that you could +set it to control backlight. I read that address using devmem2 while +running the VBIOS:\ +**\# devmem2 0xe4361254 w** + +The change is also included in libreboot 6. + +When doing this, it gave back that value. The same trick was used to get +backlight controls for T60 (see +[\#t60\_native\_notes](#t60_native_notes)). + +Further notes +------------- + +Reading **0xe4361254** (address) in Lenovo BIOS always yields FFFFFFFF, +even when writing to it (and writing to it doesn\'t affect brightness +controls). \'mtjm\' on IRC found that the buttons (Fn keys) control +/sys/class/backlight/acpi\_video0 which has no affect on 61254 +(BLC\_PWM\_CTL). This person says intel\_backlight has different values +and uses the register. devmem2 works, needs checking **lspci -vv** for +where the memory is mapped, which is different than on coreboot; mtjm +found that it was 0xec061254 on his system (X60 Tablet), and the +register value is different too. **This is relevant, because we still +don\'t know how backlight controls are actually handled. We got it +working by accident. We need to know more.**. + +Intel-gpu-tools may prove useful for further debugging: +<http://cgit.freedesktop.org/xorg/app/intel-gpu-tools/> + +mtjm says 0xe4300000 is an MMIO region of the gpu (lspci -vv shows it), +0x61254 (BLC\_PWM\_CTL) is a documented register. Searching the kernel +driver for backlight shows that in intel\_panel.c this register is used +(there is an XXX comment about finding the right value, where recent +kernels get it from. + +What we want to do is calculate a good value, instead of setting it in +devicetree.cb. mtjm says about backlight physics: it has a light source +, uses pulse width modulation (PWM) to turn it on/off, dimming is done +by spending less time on. **Note: this may not be correct; this person +says that their understanding is based on how the Lenote yeeloong +works**. + +mtjm goes on to say, that the register specifies the frequency used for +PWM in its depending on the GPU core frequency, so it might be possible +to calculate it without hardcoded laptop-specific values. Therefore, I +am supposed to find out the \'display core frequency\' (mtjm says there +might be a register for it; also, it might be in 5320 or the replay +code) and the PWM modulation frequency. +https://en.wikipedia.org/wiki/Backlight\#Flicker\_due\_to\_backlight\_dimming + +phcoder (Vladimir Serbinenko) who is author of 5320 +(review.coreboot.org) talks about \'duty cycle limit\' and \'flickering +frequency\'. + +[Back to top of page](#pagetop) + +</div> + +<div class="section"> + +T60 native graphics initialization (with backlight controls) {#t60_native_notes} +============================================================ + +**This is now obsolete. A better way was found (included in libreboot): +<http://review.coreboot.org/#/c/6731/>** + +***Also check [\#5320\_kernel312fix](#5320_kernel312fix) (to fix 3D on +kernel 3.12/higher)*** + +**The fix below was done on an earlier version of 5345 changeset +(review.coreboot.org), but should work on the current version. it is +included in libreboot 6** + +**Add backlight controls:** in *src/mainboard/lenovo/t60/devicetree.cb*, +change **gpu\_backlight** to **0x58BF58BE** + +Hold on! Check +[../misc/\#get\_edid\_panelname](../misc/#get_edid_panelname) to know +what LCD panel you have. This is important for the next step! + +Supported panels +---------------- + +[../hcl/\#supported\_t60\_list](../hcl/#supported_t60_list). + +See [\#lcd\_i945\_incompatibility](./#lcd_i945_incompatibility). + +[Back to top of page](#pagetop) + +</div> + +<div class="section"> + +i945: 3D fix (based on 5927) for kernel 3.12+ on 5320 {#5320_kernel312fix} +===================================================== + +**This is now obsolete. Merged in coreboot: +<http://review.coreboot.org/#/c/5927/>** + +**This needs to be rewritten (or better organized, or deleted?)**. This +is also now included in libreboot 6 (using the proper way, not the +7c0000 method which was a hack) + +**This was done on 5320/6 so far. The fix below is for 5320/6 which is +now obsolete. This needs to be re-done for the latest version of 5320. +The fix below is (in practise) only for reference, therefore.** + +See [\#x60\_cb5927\_testing](#x60_cb5927_testing) for the original (and +current) fix, for the replay code. Now we want to implement that on top +of <http://review.coreboot.org/#/c/5320> which is the current code for +native graphics initialization on i945. + +src/northbridge/intel/i945/gma.c (using the 7c0000 hack) on 5320: +[5320\_7c0000\_gma.c](dumps/5320_7c0000_gma.c) (rename it to gma.c, +replacing the current one). + +The above is a hack (as is the original). A better (more correct) method +is implemented in later versions of 5927, so that should also be adapted +for 5320. For now, you can use the above fix. + +The correct way to do it is to set gtt address to (end of stolen memory +- gtt size), which is what later versions of 5927 do (successfully). + +Here is some debugging output using intel\_gpu\_tools v1.2-1 (from +apt-get repositories) using tool \"intel\_gtt\": + +- kernel 3.14.4: + - with libreboot 5th release (using the 7c0000 gtt hack from + 5927/3): <http://paste.debian.net/104306> + - with coreboot+vgarom: <http://paste.debian.net/104309> +- kernel 3.2.0-60 (from apt-get repositories): + - with coreboot (no vbios or native init): + <http://paste.debian.net/104341> + +[Back to top of page](#pagetop) + +</div> + +<div class="section"> + +i945/X60: Coreboot 5927 testing (3D fix for kernel 3.12+ on replay code) {#x60_cb5927_testing} +======================================================================== + +**This is now obsolete. Merged in coreboot: +<http://review.coreboot.org/#/c/5927/>** + +**The latest version as-is (5927/11) has not been tested by me yet. +Always boot with \'drm.debug=0x06\' kernel parameter when testing +this.** + +This is the fix for 3D on kernel 3.12 and higher on i945 (ThinkPad X60 +in this case). This is for the replay code. Libreboot 5th release has a +version of this backported already (based on 5927/3 using the \'7c0000\' +hack). + +**The replay code is obsolete (see 5320 changeset on review.coreboot.org +for better version which supports more systems/screens, and then 5345 +for T60). Information here for reference since that is where the fix was +first applied.** + +Read the information on <http://review.coreboot.org/#/c/5927/>. + +For historical purposes, here is a collection of IRC logs that once +existed on this page, related to the issue: +[kernel312\_irc](dumps/kernel312_irc). + +PGETBL\_CTL differs between VBIOS (-) and native graphics init (+).\ +- PGETBL\_CTL: 0x3ffc0001\ ++ PGETBL\_CTL: 0x3f800001 + +GTT (graphics translation table) size is PGETBL\_save, max 256 KiB. BSM +(Base of Stolen Memory) is given by the bios. + +- 5927/7: [5927\_7.tar.gz](dumps/5927_7.tar.gz) (GRUB graphics are + correct now, and 3D still works) +- 5927/6: [5927\_6.tar.gz](dumps/5927_6.tar.gz) (GRUB graphics still + corrupt, 3D/everything still works after GRUB) +- 5927/5: [5927\_5.tar.gz](dumps/5927_5.tar.gz) (GRUB graphics + corrupt, 3D/everything still works after GRUB) +- 5927/3: [5927\_3.tar.gz](dumps/5927_3.tar.gz) (3D still works! + kernel 3.14.4) - the \'7c0000\' hack +- 5927/2: [5927\_2.tar.gz](dumps/5927_2.tar.gz) (3D works! kernel + 3.14.4) - the \'7c0000\' hack +- 5927/1 (didn\'t fix the 3D issue): + - [cbmem -c](dumps/5927_cbmemc) + - [/sys/class/drm/card0/error](dumps/5927_crashdump) + - [.config](dumps/5927_config) + +[Back to top of page](#pagetop) + +</div> + +<div class="section"> + +Copyright © 2014, 2015 Leah Rowe <info@minifree.org>\ +Permission is granted to copy, distribute and/or modify this document +under the terms of the Creative Commons Attribution-ShareAlike 4.0 +International license or any later version published by Creative +Commons; A copy of the license can be found at +[../cc-by-sa-4.0.txt](../cc-by-sa-4.0.txt) + +Updated versions of the license (when available) can be found at +<https://creativecommons.org/licenses/by-sa/4.0/legalcode> + +UNLESS OTHERWISE SEPARATELY UNDERTAKEN BY THE LICENSOR, TO THE EXTENT +POSSIBLE, THE LICENSOR OFFERS THE LICENSED MATERIAL AS-IS AND +AS-AVAILABLE, AND MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND +CONCERNING THE LICENSED MATERIAL, WHETHER EXPRESS, IMPLIED, STATUTORY, +OR OTHER. THIS INCLUDES, WITHOUT LIMITATION, WARRANTIES OF TITLE, +MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, +ABSENCE OF LATENT OR OTHER DEFECTS, ACCURACY, OR THE PRESENCE OR ABSENCE +OF ERRORS, WHETHER OR NOT KNOWN OR DISCOVERABLE. WHERE DISCLAIMERS OF +WARRANTIES ARE NOT ALLOWED IN FULL OR IN PART, THIS DISCLAIMER MAY NOT +APPLY TO YOU. + +TO THE EXTENT POSSIBLE, IN NO EVENT WILL THE LICENSOR BE LIABLE TO YOU +ON ANY LEGAL THEORY (INCLUDING, WITHOUT LIMITATION, NEGLIGENCE) OR +OTHERWISE FOR ANY DIRECT, SPECIAL, INDIRECT, INCIDENTAL, CONSEQUENTIAL, +PUNITIVE, EXEMPLARY, OR OTHER LOSSES, COSTS, EXPENSES, OR DAMAGES +ARISING OUT OF THIS PUBLIC LICENSE OR USE OF THE LICENSED MATERIAL, EVEN +IF THE LICENSOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH LOSSES, +COSTS, EXPENSES, OR DAMAGES. WHERE A LIMITATION OF LIABILITY IS NOT +ALLOWED IN FULL OR IN PART, THIS LIMITATION MAY NOT APPLY TO YOU. + +The disclaimer of warranties and limitation of liability provided above +shall be interpreted in a manner that, to the extent possible, most +closely approximates an absolute disclaimer and waiver of all liability. + +</div> |