linaro-dev June 2011

linaro-dev@lists.linaro.org

149 participants
196 discussions

[PM] 01/06/2011 - Minutes for the Power Management WG weekly call

by Vincent Guittot

Hi All, The minutes of the power management weekly call can be found at : https://wiki.linaro.org/WorkingGroups/PowerManagement/Meetings/2011-06-01 Summary: * A block diagram has been added to the thermal wiki page. A 1st port of thermal framework is ongoing on panda. * Powerdebug code has been modified to prepare the addition of new features (gpio, thermal) * Some issues with cpufreq tests have been raised. Vishwa is going to check if all patches for omap3 cpufreq have been pushed into the linaro kernel * a 1st version of arm cpu topo definition based on MPIDR is running. We are also going to study the interest of using FDT for the definition of the cpu topology * A 1st version of a common cpu context save/restore for cpuidle should be proposed soon. Vincent

14 years

[ACTIVITY] Graphics WG weekly status - wk22.2011

by Ilias Biris

For links and details check: https://wiki.linaro.org/WorkingGroups/Middleware/Graphics/Status/2011-06-01 == Key Points for wider discussion == * Training material request: how to release wiki page for work groups - with instructions that can be followed. Indicate which routes to take in common cases (when to release as a tarball etc). Action item to Fathi, Ricardo and Tom Gall - perhaps need to start a discussion in the mailing list also to get the feedback from the teams * Managing our monthly releases - level of quality testing may need to be tackled on a component per component basis especially for components where the correctness testing is not really there (or is challenging to implement completely). Validation team should participate as well as perhaps others (landing teams - to get some crisp baselines from teams actually using our components) == Team Highlights == * Review for the GWG cycle public plans 20110602 (today!). Check the [[https://wiki.linaro.org/Cycles/1111/PublicPlanReview|PublicPlanReview]] page! * Memory management: Jesse sent out a status report after the UDS mini-summit discussions. Jesse will coordinate these activities with Sumit and Rob. * NUX work: daily sync ups with Alexandros, Travis and Jesse trying to get NUX working. Latest big thing was the fact that NUX is trying to support the openGL shading language but in a way that would not even work on desktop. The implementation of the shading language in NUX is not correct - Alexandros to file a bug. We believe we have a solid fix coming up. * Compiz: Blur plugin is the only thing missing Travis is testing now, merge branch from our team will need to be packaged for some testing. * Validation - out of tree tests registration and providing the tests to validation team: Alexandros worked with Zygmunt and defined 2 ways to proceed. If a test does not require something special we can push it into abrek and it will be put in tree. For out of tree packages we need to inform the validation team which PPA it is going to be and what it enables so they can pull it into validation. * Managing our monthly releases: Alexandros started the discussion on how to manage the release of the GWG components. Cycles are being refactored, to use monthly releases of our components, so we may or may not have interesting work to go into the monthly release EVERY MONTH, but we should have a good process to make sure that we are enabled to release the components as needed. Automatic testing for the components, and also testing the other components for possible breakages prior to merging something in order to know how well the changes work and what they break is a challenge. Not everything we work on has built-in support for the automatic tests especially how to do the correctness testing. We will have the challenge to check component-by-component what human element of testing can be automated. NUX has a standalone test, but the tests do not cover visuals let alone that there are lots of combinations in plugins used and configurations - the task of writing tests for 100% coverage would be a real challenge, and manual testing is right now the only one applied for just the default configuration (which amounts for desktop functionality). Other possible ideas: a basic compiz functionality automatic validation may be doable (example of a screensaver plugin which could be used) eg by poking compiz via D-BUS and testing the window manager functionality of Compiz (for example, moving windows around) and using some tool to check if the drawing is as should be. * Related to the packaging, for the monthly release, a question rose what kind of setup should we have in order to release good quality tarballs. Alexandros commented that a day or two prior to the release for some testing is good enough now. Also trying to build daily packages and using the test reports from those components that have self-testing could be useful for the team. Alexandros will write up a description of what he does on the wiki * Developing further the blueprints, activities for 11.06 to be targeted (action for all) * Training request - how to do the release components for a group. We need to collect the material and make sure that all in the team have some cross-training on how to release components for the group. Maybe later push the wiki page to a general howto. == Upcoming Deliverables == * Working now to define the targets for the 11.06 release == Miscellaneous == * Sumit Semwal (TI) presented himself for the first time to the group. Welcome Sumit!! -- Ilias Biris, Aallonkohina 2D 19, 02320 Espoo, Finland Tel: +358 50 4839608 (mobile) Email: ilias dot biris at linaro dot org Skype: ilias_biris

14 years

Images vs installers

by Wookey

There has been quite a lot of discussion of image creation, how many flavours there should be, where we store them and for how long, how they get generated and delivered etc. And there were many sessions at UDS as well as a couple of threads on this list covering this. All this discussion left me feeling that people had got a little fixated on pre-generated images, and the alternative approach of using an installer has not received enough attention. Only the server sessions even mentioned this and even there we are still planning to start with an image and move to an installer later (IIRC). So I just thought I'd bring this up as a point to bear in mind as we move along. I really think we should be taking the installer option more seriously in the future, and not trying to serve the whole world of possibilities with images. There are clearly advantages to the 'just dd an image onto removable media and plug it in to get started' and having one of these available for that 'instant start' fix makes a lot of sense. I'm not suggesting we should stop doing that; this is the 'crack' to get new people addicted :-) But the more you get into having different images for different machines and purposes, the more you suffer from the combinatorial explosion problem. And all those images are actually just combinations of packages for the hardware and the software wanted, which are trivially specified and installed by a general-purpose installer (an example of which already exists in Debian, working across all architectures, using the same software to run the install as is ultimately installed on the machines). By using an installer (actually just a mini-distro image, which could be made exactly as the images we are currently making) running on the target hardware you gain the ability to make as many 'tasks' (currently images) as you like, and support as many boards as you want to support without the combinatorial explosion. And it can be skinned and pre-configured in different ways for different use-cases (fully automated/simple task selection/fully configurable, headless/gui, netboot/SD image and so on). I realise that this involves some work, but so does all that image-generation, and I do believe that the flexibility of this approach is powerful and we shouldn't ignore it to the degree we currently are. Pre-built images comes from an 'embedded systems' view of the world. Real computers can run installers to put their operating systems on and set themselves up, and we should be taking advantage of that. ARM computers _are_ real computers now and we should be treating them as such. Yes it takes a lot longer on initial boot, which is why I agree that there should be at least one 'instant gratification' image, but for real work, having to install your OS the first time you boot a board is not a big deal, and provides enormous flexibility. We can make it slick and painless. So, that's all. We don't necessarily need to have a big debate about this now, I'd really just like to make sure that this is properly on the agenda for the next cycle, and that we don't all get so stuck in the 'everything must be supplied as pre-generated image' mindset that we back ourselves into a very inefficient corner. Wookey -- Principal hats: Linaro, Emdebian, Wookware, Balloonboard, ARM http://wookware.org/

14 years

Gerrit userstory for multi-branch development

by Paul Sokolovsky

Hello Arnd, I'd like to follow up to the discussion which took place during "Android Code Review" session at LDS (https://wiki.linaro.org/Platform/Android/Specs/AndroidCodeReview). You expressed concern that Gerrit is not too flexible for working with multiple topic branches, in particular, that it enforces work against single (master) branch (as far as I understood). Well, looking at AOSP's Gerrit instance, https://review.source.android.com/ one can see that there's a "branch" field present, and shown in the list of patches, and there're patches which reference non-master branches (here's list for "froyo" branch for example: https://review.source.android.com/#q,status:open+branch:froyo,n,z ). So, it at least allows to label a patch with a branch it is submitted against. So, can you please elaborate on the concerns you expressed? A generalized user story and specific example would be very helpful. (And please keep in mind that I still know little about Gerrit, so if the above doesn't relate directly to your concerns, I'm sorry, that's why I'd like to collect more detailed info on Gerrit's features/misfeatures people know). Thanks, Paul

14 years

Memory Management Mini-Summit Report

by Jesse Barker

Memory Management Mini-Summit Linaro Developer Summit, Budapest, May 9-11, 2011 ================================================= Hi all. Apologies for this report being so long in coming. I know others have thrown in their perceptions and opinions on how the mini-summit went, so I suppose it's my turn. Outcomes: --------- * Approach (full proposal under draft, to be sent to the lists below) - Modified CMA for additional physically contiguous buffer support. - dma-mapping API changes, enhancements and ARM architecture support. - "struct dma_buf" based buffer sharing infrastructure with support from device drivers. - Pick any "low-hanging fruit" with respect to consolidation (supporting the ARM arch/sub-arch goals). * Proposal for work around allocation, mapping and buffer sharing to be announced on: - dri-devel - linux-arm-kernel - linux-kernel - linux-media - linux-mm - linux-mm-sig * Communication and Meetings - New IRC channel #linaro-mm-sig for meetings and general communication between those working on and interested in these topics (already created). - IRC meetings will be weekly with an option for the consituency to decide on ultimate frequency (logs to be emailed to linaro-mm-sig list). - Linaro can provide wiki services and any dial-in needed. - Next face-to-face meetings: . Linaro mid-cycle summit (August 1-5, see https://wiki.linaro.org/Events/2011-08-LDS) . Linux Plumbers Conference (September 7-9, see http://www.linuxplumbersconf.org/2011/ocw/proposals/567) . V4L2 brainstorm meeting (Hans Verkuil to update with details) Overview and Goals for the 3 days: ---------------------------------- * Day 1 - Component overviews, expected to spill over into day 2 * Day 2 - Concrete use case that outlines a definition of the problem that we are trying to solve, and shows that we have solved it. * Day 3 - Dig into the lower level details of the current implementations. What do we have, what's missing, what's not implemented for ARM. This is about memory management, zero-copy pipelines, kernel/userspace interfaces, memory management, memory reservations and much more :-) In particular, what we would like to end up with is: * Understand who is working on what; avoid work duplication. * Focus on a specific problem we want to solve and discuss possible solutions. * Come up with a plan to fix this specific problem. * Start enumerating work items that the Linaro Graphics WG can work on in this cycle. Day 1: ------ The first day got off to a little bit of a stutter start as the summit scheduler would not let us indicate that our desired starting time was immediately after lunch, during the plenaries. However, that didn't stop people from flocking to the session in droves. By the time I made the kickoff comments on why we were there, and what we were there to accomplish (see "Overview and Goals for the 3 days" above), we had brought in an extra 10 chairs and there were people on the floor and spilling out into the hallway. Based upon our experiences from the birds-of-a-feather at the Embedded Linux Conference, 2 things dominated day 1. First things first, I assigned someone to take notes ;-). Etherpad made it really easy for people to take notes collectively, including those participating remotely, and for everyone to see who was writing what, but we definitely needed someone whose focus would be capturing the proceedings, so thanks to Dave Rusling for shouldering that burden. The second thing was that we desperately needed an education in each others components and subsystems. Without this, we would risk missing significant areas of discussion, or possibly even be violently agreeing on something without realizing it. So, we started with a series of component overviews. These were presentations on the order of 20 minutes with some room for Q&A. On day 1, we had: * V4L2 - Hans Verkuil * DRM/GEM/KMS - Daniel Vetter * TTM - Thomas Hellstrom * CMA - Marek Szyprowski * VCMM - Zach Pfeffer All of these (as well as the ones from day 2) are available through links on the mini-summit wiki (https://wiki.linaro.org/Events/2011-05-MM). Day 2: ------ The second day got off to a bit better a start than did day 1 as we more clearly communicated the start time to everyone involved, and forgot about the summit scheduler. We (conceptually) picked up where day 1 left off with one more component overview: * UMP - Ketil Johnson and, covered the MediaController API for good measure. From there, we spent a fair amount of time discussing use cases to illustrate our problem space. We started (via pre-summit submissions) with a couple of variations on what amounted to basically the same thing. I think the actual case is probably best illustrated by the pdf slides from Sakari Ailus (see the link on the mini-summit wiki). Basically, we want to take a video input, either from a camera or from a file, decode it, process it, render to it and/or with it and display it. These pipeline stages may be handled by hardware, by software on the CPU or some combination of the two; each stage should be handled by accepting a buffer from the last stage and operating on it in some fashion (no copies wherever possible). It turned out that still image capture can actually be a more complicated version of this use case, but even something as simple as taking input through the camera and displaying it (image preview) can involve much of the underpinnings required to support the more complicated cases. We may indeed start with this simple case as a proof-of-concept. Once we had the use case nailed down, we moved onto the actual components/subsystems that would need to share buffers in order for the use case to work properly with the zero-copy (or at least minimal-copy) requirement. We had: * DRM * V4L2 * fbdev * ALSA * DSP * User-space (kind of all encompassing and could include things like OpenCL, which also makes an interesting use case). * DVB * Out-of-tree GPU drivers We wound out the day by discussing exactly what metadata we would want to track in order to enable the desired levels of sharing with simultaneous device mappings, cache management and other considerations (e.g., device peculiarities). What we came up with is a struct (we called it "dma_buf") that has the following info: * Size * Creator/Allocator * Attributes: - sharable? - contiguous? - device-local? * Reference count * Pinning reference count * CPU cache management data * Device private data (e.g., quirky tiling modes) * Scatter list * Synchronization data (for managing in-flight device transactions) * Mapping data These last few (device privates through mapping data) are lists of data, one for each device that has a mapping of the buffer. The mapping data is nominally an address and per-device cache management data. We actually got through the this part fairly quickly. The biggest part of the discussion was what to use for handles/identifiers in the buffer sharing scheme. The discussion was between global identifiers like GEM uses, or file descriptors as favored by Android. Initially, there was an informal consensus around unique IDs, though it was not a definitive decision (yet). The atomicity of passing file descriptors between processes makes them quite attractive for the task. Day 3: ------ By the third day, there was a sense of running out of time and really needing to ensure that we left with a reasonable set of outcomes (see the overview and goals section above). In short, we wanted to make sure that we had a plan/roadmap, a reasonably actionable set of tasks that could be picked up by Linaro engineers and community members alike, and that we would not only avoid duplicating new work, but also reduce some of the existing code duplication that got us to this point in the first place. But, we weren't done. We still had to cover the requirements around allocation and explore the dma-mapping and IOMMU APIs. This took most of the day, but was a quite fruitful set of discussions. As with the rest of the discussions, we focused on leveraging existing technologies as much as possible. With allocations, however, this wasn't entirely possible as we have devices on ARM SoCs that do not have an IOMMU and require physically contiguous buffers in order to operate. After a fair amount of discussion, it was decided that a modified version of the current CMA (see Marek's slides linked from the wiki). It assumes the pages are movable and manages them and not the mappings. There was concern that the API didn't quite fit with other related API, so the changes from the current state will be around those details. On the mapping side, we focused on the dma-mapping API with appropriate layering on the IOMMU API where appropriate. Without going into crazy detail, we are looking at something like 4 implementation s of the dma_map_ops functions for ARM: with and without IOMMU, with and without bounce buffer (these last two exist, but not using the dma_map_ops API). Marek has put out patches for comment on the IOMMU based implementation of this based upon work he had in progress. Also in the area of dma_map_ops, the sync related API need a start address and offset, and the alloc and free need attribute parameters like map and unmap already have (to support cacheable/coherent/write-combined). In the "not involving dma_map_ops" category, we have a couple of changes that are likely to be non-trivial (not that any of the other proposed work is). It was proposed to modify (actually, the word thrown about in the discussions was "fix") dma_alloc_coherent for ARM to support unmapping from the kernel linear mapping and the use of HIGHMEM; two separate implementations, configured at build-time. And, last but not least, there was a fair amount of concern over the cache management API and its ability to live cleanly with the IOMMU code and to resist breakage from other architecture implementations. At this point, we reviewed what we had done and finalized the outcomes (see the outcomes section at the top). And, with a half an hour to spare, I re-instigated the file descriptors versus unique identifiers discussion from day 2. I think file descriptors were winning by the end (especially after people started posting pointers to code samples of how to actually pass them between processes).... Attendees: ---------- I will likely miss people here trying to list out everyone, especially given that some of the sessions were quite literally overflowing the room we were in. For as accurate an account of attendance as I can muster, check out the list of attendees on the mini-summit wiki page or the discussion blueprints we used for scheduling: https://wiki.linaro.org/Events/2011-05-MM#Attendees https://blueprints.launchpad.net/linaro-graphics-wg/+spec/linaro-graphics-m… https://blueprints.launchpad.net/linaro-graphics-wg/+spec/linaro-graphics-m… https://blueprints.launchpad.net/linaro-graphics-wg/+spec/linaro-graphics-m… The occupants of the fishbowl (the front/center of the room in closest proximity to the microphones) were primarily: Arnd Bergmann Laurent Pinchart Hans Verkuil Mauro Chehab Daniel Vetter Sakari Ailus Thomas Hellstrom Marek Szyprowski Jesse Barker The IRC fishbowl seemed to consist of: Rob Morell Jordan Crouse David Brown There were certainly others both local and remote participating to varying degrees that I do not intend to omit, and a special thanks goes out to Joey Stanford for arranging a larger room for us on days 2 and 3 when we had people sitting on the floor and spilling into the hallway during day 1.

14 years

[PATCH] SMDKV310: CPU fequency and mmc_pre_ratio modified

by Chander Kashyap

Modifies CPU Frequency to 1GHz and removes hard coding of mmc_pre_ratio for MMC Channel2 in FSYS2 register. Signed-off-by: Chander Kashyap <chander.kashyap(a)linaro.org> --- board/samsung/smdkv310/lowlevel_init.S | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/board/samsung/smdkv310/lowlevel_init.S b/board/samsung/smdkv310/lowlevel_init.S index 359cff4..04f6579 100644 --- a/board/samsung/smdkv310/lowlevel_init.S +++ b/board/samsung/smdkv310/lowlevel_init.S @@ -170,7 +170,7 @@ system_clock_init: * COREM1_RATIO[8] 0x7 * COREM0_RATIO[4] 0x3 */ - ldr r1, =0x01133730 + ldr r1, =0x0133730 ldr r2, =0x14500 @CLK_DIV_CPU0_OFFSET str r1, [r0, r2] @@ -245,7 +245,7 @@ system_clock_init: str r1, [r0, r2] /* MMC[2:3] */ - ldr r1, =0x000f020f /* 800(MPLL) / (15 + 1) */ + ldr r1, =0x000f000f /* 800(MPLL) / (15 + 1) */ ldr r2, =0x0C548 @ CLK_DIV_FSYS2 str r1, [r0, r2] -- 1.7.4.1

14 years

Thumb-2 kernel on imx

by Dave Martin

Hi there Eric, I have some results now from trying a Thumb-2 kernel on our various trees for imx: * It "works" on the packaged 2.6.38 kernel tree (linux-linaro-natty), but I can't test things the kernel doesn't support (like power management). [ John, is it worth trying to turn this on for the vanilla linaro tree and seeing whether it causes problems for anyone? Are there any particular tests I should do? ] * The landing team trees contain some power management code that doesn't build for Thumb-2 -- if you can suggest who to discuss that with / where to propose patches, that would be great. (The affected code appears simple to patch.) * Many .align directives should be added, where inline data words are declared in .S files. I can advise further on this / suggest a patch. Only the landing trees appear to be affected. * The lt-2.6.38 and linaro-lt-mx5-2.6.35 trees don't seem to boot for me, either in the default configuration (from debian.linaro/config/) or in Thumb-2. I may be doing something wrong... * The lt-2.6.38 tree has CONFIG_FIQ=y. I believe this might be a bug: this option is implicitly enabled in sound/soc/imx/Kconfig if any imx SoC audio support is built. I believe that FIQ is may not be used by any driver applicable to the mx5 platforms, but I'd like someone to clarify this, since I'm not famliar with exactly what platforms exist and their hardware configuration. If FIQ might be used, then some work is needed in plat-mxc/ssi-fiq.S, since that code is not currently Thumb-2 compatible. Note that all exceptions are entered in Thumb-2 in a Thumb-2 kernel. There are a couple of core arm patches I recently upstreamed which would also be needed. I'm guessing the best way forward is to discuss these with someone on the landing team. None of the problems appears to affect the code that is currently upstream. Cheers ---Dave

14 years, 1 month

Proposal to enable CONFIG_THUMB2_KERNEL for vexpress

by Dave Martin

Hi there John, I've tested the linux-linaro-natty tree with CONFIG_THUMB2_KERNEL on vexpress, and it seems to work well. Since we have reasonable confidence in the status of vexpress for Thumb-2 anyway, the start of this cycle seems a good opportunity to switch to Thumb-2 for this platform. Which packaging tree is the active one for the 11.11 cycle? I guess that would be the appropriate place for this config change. Cheers ---Dave Options to add: CONFIG_THUMB2_KERNEL=y CONFIG_THUMB2_AVOID_R_ARM_THM_JUMP11=y (this should get turned on automatically: if so, leave it implicit) Options to remove: CONFIG_FPE_NWFPE=n CONFIG_FPE_FASTFPE=n

14 years, 1 month

[RFC] Moinmoin ratings plugin

by Ilias Biris

Folks I recently came up with a list of ideas proposed for the problem of the development cycle. I put those in the wiki, however it soon dawned on me that others would need to actually edit the wiki in order to give feedback. Each user could add some comment or +1 or something like that. Altogether deciphering the results could mean some work going through the user comments. So I want to have a quick and easy way for ratings on the ideas. Moinmoin supports star ratings, like described here: http://moinmo.in/RatingSystemForMoin. Basically it allows readers to rate options given in the wiki page, without having to edit the page, just click on the stars. I made an IT request to have this plugin installed but was asked to start a discussion in the list, as the usefulness of this plugin is doubted. Am I the only one needing some quick way for readers to rate ideas put on the wiki? If you also have the same need, +1 it by responding to this thread :-) Hopefully we can have this support added. Thank you -- Ilias Biris, Aallonkohina 2D 19, 02320 Espoo, Finland Tel: +358 50 4839608 (mobile) Email: ilias dot biris at linaro dot org Skype: ilias_biris

14 years, 1 month

Should we include patches sent to devicetree-discuss in our stats?

by Guilherme Salgado

Hi folks, There is a significant number of patches sent to devicetree-discuss that were CCed to patches(a)linaro.org and thus will be counted when generating our patch stats. However, if this is just a mailing list for discussion and the patches are actually being sent to the lkml (or other ML like linux-arm-kernel) as well, they will end up being double counted, which is not what you want. I'd appreciate if somebody could clarify to me what's the purpose of the devicetree-discuss ML and whether or not we should be ignoring patches sent there. (Note that even if the right thing to do is to ignore patches sent there it's fine, for simplicity's sake, for you all to continue CCing patches sent there to patches(a)l.o -- we'll just ignore them when generating stats). Cheers, -- Guilherme Salgado <https://launchpad.net/~salgado>

14 years, 1 month

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linaro-dev June 2011