Re: Touchpad accel, spirals and xset
To prove, first turn off how the existing module triggers recalibrations Reproduced without changing parameters or a nose. Turning off the recalibrations was just to allow miscalibration to persist for demonstration purposes. Ie, starting from first principles to show my reasoning. I agree, it does seem that the calibration as a result of jumpiness might cause symptoms. One thing I realised I could have emphasised is that the attempted recalibration based on jumpiness is self perpetuating. Much like why post_interrupt_delay didn't work. We're trying to think of things the device developers would have already thought about. I can't think of a way to know when it is safe to recalibrate. That is where I explained what was described as spew, being helpful. I just fired up the tech specshttp://wiki.laptop.org/go/Image:KGDMFA001-non-confidential.pdf(the xo displays it correctly), and page 14 has the point about auto self recalibration... --- 7) Automatic calibration setting command Enable/Disable *C ver This command sets whether to do the calibration automatically when the following states are generated. a. The high-speed operation not generated in the normal operation when continuing. b. When you continuously generate the same position for ten seconds or more. For (b), 10 seconds is a long time. But does anyone know about (a), and if/why we do/dont use auto calib without the firmware module recalibs? 2010/1/21 James Cameron qu...@laptop.org On Thu, Jan 21, 2010 at 01:30:06AM +0100, James Zaki wrote: The first thing I suspect most people do while waiting for the gui to become responsive is try to move the curser. Yes, I've seen children do that. Or press keyboard keys hoping it will go faster booting. It seems to work for them because their perception of time is altered by interacting. The init of the psmouse module triggers a calibration. Tested ... holding a finger on the touchpad during boot ... does cause jumpyness. To prove, first turn off how the existing module triggers recalibrations (I will explain the problem with one of them in a moment) --- cd /sys/module/psmouse/parameters echo 0 jumpy_delay; echo 0 spew_delay --- Now give your xo a 5-finger-salut. The regular 4-finger-salut is here but just before hitting that final fn key, try rest a finger on the touchpad (the nose squished a bit also works too). The bigger the touch, the greater areas are miscalibrated. Reproduced without changing parameters or a nose. One way to reproduce was with a finger in one corner tap the other corner whilst lifting the first finger. Doing something like this a few times (basically triggering the recalibrate by imperfect use) will cause the calibration to occur whilst your fingers are there. Reproduced easily. (all above 802 on XO-1) I agree, it does seem that the calibration as a result of jumpiness might cause symptoms. I can't think of a way to know when it is safe to recalibrate. -- James Cameron http://quozl.linux.org.au/ ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Touchpad accel, spirals and xset
james -- thanks for taking a fresh look at this. james wrote: Thanks Martin, With some help from the people at #olpc-devel such as pgf, I was able to look at where I needed to to test some theories. Looking at the code in hgpk.c that runs on the xo-1 I'm testing on, The first thing I suspect most people do while waiting for the gui to become responsive is try to move the curser. The init of the psmouse module triggers a calibration. that's certainly true, but i think it happens pretty early -- the kernel is initialized by the time the dots start circling the XO guy. and we don't really have any control over it. Perhaps this is already clear to all but for completeness, calibrating the capacitive display with a finger on the pad is a (the?) cause of jumpyness/weirdness in control. just a cause, i believe. if it were the only cause, i think we'd be having a lot fewer issues. as you've observed, multiple digits too close to the pad at once can cause jumpiness. overreacting to that by immediately recalibrating isn't the answer, though, for this reason (i.e., the fingers may well still be there). To prove, first turn off how the existing module triggers recalibrations (I will explain the problem with one of them in a moment) --- cd /sys/module/psmouse/parameters echo 0 jumpy_delay; echo 0 spew_delay --- Now give your xo a 5-finger-salut. The regular 4-finger-salut is herehttp://wiki.laptop.org/go/Recalibrating_Touchpadbut just before hitting that final fn key, try rest a finger on the touchpad (the nose squished a bit also works too). The bigger the touch, the greater areas are miscalibrated. (useful link1 http://www.alps.com/e/csr/value/val_new.html, link2http://www.cirque.com/technologies/glidepoint.aspx ) To regain control, just do the regular 4-finger-salut for recalibration. Without a recalibration, the touchpad rests consistantly miscalibrated (heightened sensitivity). sure. Spew I believe the spew_delay (originally 1ms) is our saviour. From hgpk.c... /* * We have no idea why this particular hardware bug occurs. The touchpad * will randomly start spewing packets without anything touching the * pad. This wouldn't necessarily be bad, but it's indicative of a * severely miscalibrated pad; attempting to use the touchpad while it's * spewing means the cursor will jump all over the place, and act drunk. * * The packets that are spewed tend to all have deltas between -2 and 2, and * the cursor will move around without really going very far. It will * tend to end up in the same location; if we tally up the changes over * 100 packets, we end up w/ a final delta of close to 0. This happens * pretty regularly when the touchpad is spewing, and is pretty hard to * manually trigger (at least for *my* fingers). So, it makes a perfect * scheme for detecting spews. */ I've not read the spec (at a guess I'd say touchpad self tuning) but the spew sounds perfect to trigger a recal! So probably not a bug, nor miscalibrated pad, especially with such stable deltas. -- echo 1 spew_delay After a moment of not touching, the recalibrate is triggered and the cursor responds as expected. i don't really understand what you're saying above. why do you think that the when the pad emits streams of packets on its own, which don't represent any real motion, that it's not a bug? Jumpyness recalibration --- I believe that the recalibration after detecting jumpyness (x/y deltas discard_threshold) is causing more problems than its solves, since jumpyness happens when fingers are on/near the touchpad. One way to reproduce was with a finger in one corner tap the other corner whilst lifting the first finger. Doing something like this a few times (basically triggering the recalibrate by imperfect use) will cause the calibration to occur whilst your fingers are there. Another (more difficult) way was to have ones index finger touching normally, but the adjacent middle finger parallel and close to the touch surface. This also causes deltas greater than discard_threshold, and triggeres touchpad-recalibration avec fingers. It is probably that under ideal use with dodgy hardware, this would be a good thing. But from what I have seen and read, I think the touchpad firmware should not be assumed to need too many hacks. So i'm not sure if spew or jumpyness came first, but with no jumpy_delay (ie. bypass jumpyness recalibration) and default spew_delay of 1, I dont have any weirdness with the touchpad. i think you may not be aware of the long history of issues with this touchpad. fixing the pad's errant behavior in the lab, or in a climate controlled home, is easy. the touchpads don't misbehave in those conditions, much. but in the uncontrolled environment of a classroom in the
Re: Touchpad accel, spirals and xset
james wrote: One thing I realised I could have emphasised is that the attempted recalibration based on jumpiness is self perpetuating. Much like why post_interrupt_delay didn't work. We're trying to think of things the device developers would have already thought about. very true -- the goal of all the recent generations of that driver has been to figure out when its safe to recalibrate (as well as when it's necessary). the new driver does a better job of that than the old driver, but if someone is insistent on having two fingers on the touchpad, or whatever, we'll almost certainly recalibrate at the wrong moment. I can't think of a way to know when it is safe to recalibrate. That is where I explained what was described as spew, being helpful. I just fired up the tech specshttp://wiki.laptop.org/go/Image:KGDMFA001-non-confidential.pdf(the xo displays it correctly), and page 14 has the point about auto self recalibration... --- 7) Automatic calibration setting command Enable/Disable *C ver This command sets whether to do the calibration automatically when the following states are generated. a. The high-speed operation not generated in the normal operation when continuing. b. When you continuously generate the same position for ten seconds or more. For (b), 10 seconds is a long time. right. too long to let the pad sit and spew. is that what you mean? But does anyone know about (a), yes, that's a good question. i think i used to understand it as referring to a failed driver-induced switch from 3-byte to 6-byte mode, but i may be misremembering. richard may remember better. and if/why we do/dont use auto calib without the firmware module recalibs? i don't understand your question. paul =- paul fox, p...@laptop.org ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: [Fwd: xorg.conf for the XO-1]
On Thu, Jan 21, 2010 at 03:06:14PM -0300, Bernie Innocenti wrote: I remember getting rid of all the manual input device configuration on the transition to Xorg 1.5. FWIW it works fine without any xorg.conf at all on Debian. It has hal running, though. CU Sascha -- http://sascha.silbe.org/ http://www.infra-silbe.de/ signature.asc Description: Digital signature ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: [Fwd: xorg.conf for the XO-1]
On Thu, 2010-01-21 at 20:37 +0100, Sascha Silbe wrote: On Thu, Jan 21, 2010 at 03:06:14PM -0300, Bernie Innocenti wrote: I remember getting rid of all the manual input device configuration on the transition to Xorg 1.5. FWIW it works fine without any xorg.conf at all on Debian. It has hal running, though. Sadly, we have hal running on F-11, too :) -- // Bernie Innocenti - http://codewiz.org/ \X/ Sugar Labs - http://sugarlabs.org/ ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: [Server-devel] Technical questions
On Thu, Jan 21, 2010 at 04:18:24PM +0100, Eustace Amah wrote: One of the problem that am experiencing now is that I configured the 15 APs with same ESSID, different channels(1,6,11) shared among them and located all around the school. Remember that the APs are configured with different subnet from the lease of DHCP server but when more than 3 XO tries to connect it knocks everyone out immediately. The APs are PoE enabled. The models are Cisco Small Business Model WAP4410N. I have increased the power to the APs. Any solution to this? There's not enough problem data above to reduce the possible causes to something workable, but I can suggest data to capture and a way to test for one particular problem. Additional problem data needed: - what does knocks everyone out immediately mean? Are other wireless users losing connectivity? Do the XO laptops remain associated (left-hand LED on)? Do the APs remain accessible through their web interface during the symptom? - what does iwlist eth0 scan show on an XO laptop? (Start Terminal, become root, type script scan.log, press enter, type iwlist eth0 scan, press enter, repeat the scan a few more times, type exit, send me the scan.log file), Testing for too many APs: - turn off 12 APs leaving three running on different channels; does the symptom still occur? You can skip this test if it is impractical. The purpose of the test is to prevent noise in the commons. - reduce the transmit power on all APs to the minimum value; does the symptom still occur? I've reviewed the WAP4410N product specifications [1]. The XOs will be operating 802.11g, so that is the important thing to look for in the specifications. The WAP4410N has 2 dBi antenna, transmit power of up to 17.5 dBm, and receiver sensitivity of -73 dBm. The specifications suggest it is an indoor unit. Check your environment; make sure the product is not being operated below 0 degrees C, above 40 degrees C, or above 85% humidity. I wasn't able to find what the current firmware version is, because I've no obligation from Cisco. You should check to see if a firmware upgrade is available. References: 1. http://www.cisco.com/en/US/prod/collateral/wireless/ps5678/ps10047/ps10052/data_sheet_c78-501860.html - -Original Message- From: Martin Langhoff [mailto:martin.langh...@gmail.com] Sent: Thursday, January 21, 2010 1:09 PM To: James Cameron; aklei...@sonic.net; Reuben K. Caron; taiwo.alabi; Eustace Amah; server-de...@lists.laptop.org; Emeka Lewis Nwankwo; kene.ijezie Subject: Re: [Server-devel] Technical questions On Thu, Jan 21, 2010 at 12:28 PM, Martin Langhoff martin.langh...@gmail.com wrote: 3 - Define how many users you can connect to an AP -- some APs have configured hard limits in the software they ship. If you have to guess, assume ~40 as the upper limit. Let's reword that as: assume 30, which is where most APs start having problems. If you are using OpenWRT, you can probably support 40. If you have tested your AP, then you'll know for real. In general, it is very hard to go over 40 active nodes per channel; this is mainly due to limitations of sharing the commons of the radio spectrum. High end APs may be able to operate different antennas in different channels -- so one AP acts as if it were 3, working on 1, 6 and 11. cheers, m -- martin.langh...@gmail.com mar...@laptop.org -- School Server Architect - ask interesting questions - don't get distracted with shiny stuff - working code first - http://wiki.laptop.org/go/User:Martinlanghoff -- James Cameron http://quozl.linux.org.au/ ___ Server-devel mailing list server-de...@lists.laptop.org http://lists.laptop.org/listinfo/server-devel
[Fwd: Re: xorg.conf for the XO-1]
[cc += pgf, de...@laptop.org] Maybe you know something about it? Forwarded Message From: Bernie Innocenti ber...@codewiz.org To: Daniel Drake d...@laptop.org Cc: Michael Stone michael.r.st...@gmail.com, Raul Gutierrez Segales r...@rieder.net.py, Chris Ball c...@laptop.org, Dennis Gilmore den...@ausil.us Subject: Re: xorg.conf for the XO-1 Date: Wed, 20 Jan 2010 14:50:48 -0300 [cc += cjb, dgilmore] On Tue, 2010-01-19 at 08:40 -0600, Daniel Drake wrote: 2010/1/19 Bernie Innocenti ber...@codewiz.org: I remember getting rid of all the manual input device configuration on the transition to Xorg 1.5. Does anyone remember why these sections were resurrected later on? have you checked fedora changelogs/cvs history? ausil (Dennis Gilmore) committed it, probably for someone else. revision 1.1 date: 2008/06/03 19:21:46; author: ausil; state: Exp; updated xorg.conf file and olpc-login Does anyone remember why this was necessary? -- // Bernie Innocenti - http://codewiz.org/ \X/ Sugar Labs - http://sugarlabs.org/ ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: [Server-devel] Technical questions
On Thu, Jan 21, 2010 at 3:45 AM, James Cameron qu...@laptop.org wrote: There are rules of thumb, and there is engineering. I have two thumbs and no engine in me, so I prefer the former. Is there any simple 5-step guide to make an _initial_ antenna placement frequency selection for APs? It will of course not be perfect. I have several books on wifi but I always wish for a simple approach. Something that starts with 1 - Get a floorplan of the building 2 - Test (or guess if you haven't been there) if the construction material for all/most walls blocks/reflects wifi radio signals. Same with floor/ceiling for multi-storey buildings. (It is always possible that some walls are different than ohers and block the signal - that's something to explore once on-site) 3 - Define how many users you can connect to an AP -- some APs have configured hard limits in the software they ship. If you have to guess, assume ~40 as the upper limit. A - If the walls block wifi A1 - Are your classrooms more than N users (N being the limit defined in step 3)? You can place 2 APs per classroom - in channels 1 and 11. Plus some APs in the common (presumably open) areas (use strategy B1 for open areas). B - If the walls do not block wifi B1 - Draw circles on the floorplan with the expected radius of reach of the AP, so that you got the areas you care about well covered. Write down in pencil a 1, 6 or 11 in each circle. The circles can overlap, but only if their frequencies are different. Of course AP placement will also depend on where you can place an AP so that it is safe for the kids around, protected from the environment, secure, and with power and ethernet wiring. cheers m -- martin.langh...@gmail.com mar...@laptop.org -- School Server Architect - ask interesting questions - don't get distracted with shiny stuff - working code first - http://wiki.laptop.org/go/User:Martinlanghoff ___ Server-devel mailing list Server-devel@lists.laptop.org http://lists.laptop.org/listinfo/server-devel
Re: [Server-devel] Technical questions
One of the problem that am experiencing now is that I configured the 15 APs with same ESSID, different channels(1,6,11) shared among them and located all around the school. Remember that the APs are configured with different subnet from the lease of DHCP server but when more than 3 XO tries to connect it knocks everyone out immediately. The APs are PoE enabled. The models are Cisco Small Business Model WAP4410N. I have increased the power to the APs. Any solution to this? -Original Message- From: Martin Langhoff [mailto:martin.langh...@gmail.com] Sent: Thursday, January 21, 2010 1:09 PM To: James Cameron; aklei...@sonic.net; Reuben K. Caron; taiwo.alabi; Eustace Amah; server-devel@lists.laptop.org; Emeka Lewis Nwankwo; kene.ijezie Subject: Re: [Server-devel] Technical questions On Thu, Jan 21, 2010 at 12:28 PM, Martin Langhoff martin.langh...@gmail.com wrote: 3 - Define how many users you can connect to an AP -- some APs have configured hard limits in the software they ship. If you have to guess, assume ~40 as the upper limit. Let's reword that as: assume 30, which is where most APs start having problems. If you are using OpenWRT, you can probably support 40. If you have tested your AP, then you'll know for real. In general, it is very hard to go over 40 active nodes per channel; this is mainly due to limitations of sharing the commons of the radio spectrum. High end APs may be able to operate different antennas in different channels -- so one AP acts as if it were 3, working on 1, 6 and 11. cheers, m -- martin.langh...@gmail.com mar...@laptop.org -- School Server Architect - ask interesting questions - don't get distracted with shiny stuff - working code first - http://wiki.laptop.org/go/User:Martinlanghoff ___ Server-devel mailing list Server-devel@lists.laptop.org http://lists.laptop.org/listinfo/server-devel
Re: [Server-devel] Technical questions
On Thu, Jan 21, 2010 at 4:18 PM, Eustace Amah ea...@slb.com wrote: One of the problem that am experiencing now is that I configured the 15 APs with same ESSID, different channels(1,6,11) shared among them and located all around the school. Excellent. Remember that the APs are configured with different subnet from the lease of DHCP not really. They are within a larger subnet -- the DHCP server knows not to assign certain IP addresses. But do not tell the AP that it is within that subnet, just tell it the IP address it has. Make sure you are not running the AP as a router. ... server but when more than 3 XO tries to connect it knocks everyone out immediately. Weird - time to complain to Cisco... The APs are PoE enabled. The models are Cisco Small Business Model WAP4410N. I have increased the power to the APs. That's a good initial guess. cheers, m -- martin.langh...@gmail.com mar...@laptop.org -- School Server Architect - ask interesting questions - don't get distracted with shiny stuff - working code first - http://wiki.laptop.org/go/User:Martinlanghoff ___ Server-devel mailing list Server-devel@lists.laptop.org http://lists.laptop.org/listinfo/server-devel
[Server-devel] multiple users of an xo
I expect to be working with a school which runs two sessions. As a result each XO is shared by two students, one from each session. 1 - (probably a Sugar issue) - each of the two students should have their own independent Journal (and backup-restore). 2 - each student should have an independent registration on the schoolserver (esp. including Moodle). 3 - the school supports grades 1-8 so that students need to be registered in Moodle by grade (not in all courses). 4 - teachers can be registered in that role by normal Moodle procedures. The current registration scheme is based on the xo's serial number. Does anyone have a suggestion as to how this should be managed? There has been talk re SoaS on how to register user's on the schoolserver independent of a serial-number. Has this reached a concensus? On a slightly different topic. I have a schoolserver installed with XS 6 but OLE Nepal's version of XO (0.82 variant). OLE Nepal has made registration automatic (the menu now shows only shutdown and control panel as options). Does anyone know where that code is in Sugar so I can execute it from the command line? Tony Tony ___ Server-devel mailing list Server-devel@lists.laptop.org http://lists.laptop.org/listinfo/server-devel
