After upgrading from kernel 2.4.26-gentoo-r9 the modem will only connect to the internet at 9600 baud. First noticed when 2.4.26-gentoo-r10 came out. neither of the later updates (r11 or r12) seems to have resolved the issue. Several things were updated on my system on the same day so it took a while to discover that the modem will connect at > 40000 baud with 2.4.26-gentoo-r9. I am currently using this older kernel. Modem is a 'U.S. Robotics 56K Voice EXT' on ttyS1. I am using KPPP on KDE 3.3.1 but get the same problem with wvdial 1.53. Reproducible: Always Steps to Reproduce: 1. Boot system with kernel > 2.4.26-gentoo-r9 2. log in and run wvdial to connect to internet Actual Results: connect information indicates connected at 9600. Access to internet is very very slow. 'emerge sync' took around 2.5 hours to complete before I tried downgrading to kernel 2.4.26-gentoo-r9 Expected Results: Connect to internet at usual speed which is normally above 44000 baud
did downgrading the kernel help?
not clear what that has to do with kernel! speed is negotiated between modems, not between computer and modem. what speed does the modem reports when you open dial-up connection in minicom, using ATD... command? settings for minicom are: - 115200 bauds - 8N1 - hardware flow control
I did not think that this could be kernel related either but after some research, I found that the only thing that I need do change to get this problem is to boot the machine with a kernel later than 2.4.26-gentoo-r9 OK, I installed minicom and with kernel 2.4.26-gentoo-r9 and the settings suggested for minicom, I got the following connect details: CONNECT 44000/ARQ/V90/LAPM/V42BIS Rebooted machine with kernel 2.4.26-gentoo-r12 and made sure minicom settings were as suggested again. This gives the following connect details: CONNECT 9600/ARQ/V34/LAPM/V42BIS Rebooted back to kernel 2.4.26-gentoo-r9 and received the following connect details: CONNECT 44000/ARQ/V90/LAPM/V42BIS So, the only difference between each connect was the version of the kernel running. As for the difference between the compilation, I used the same kernel configuration file for both kernels. I checked for anything new after loading up my default 2.4.26 configuration and did not find anything that I believed needed to be changed. Was there some change to the serial port code in the kernel between release 9 and 10?
Strange. If it is for real then it could only mean one thing: the real speed of serial connection between modem and computer is 9600, no matter what you set in minicom and modem use this speed as its limit form modem-to-modem speed. For testing this, please connect with minicom and set modem to report serial connection speed. It must be an AT command described in modem's manual. If it reports 115200... well, I don't have a rational explanation for this case.
OK, I tested as suggested and here are my findings. Using kernel 2.4.26-gentoo-r9 Switch on modem. Run minicom Get current status from modem using ati 4 which gives: U.S. Robotics 56K Voice EXT Settings... B0 E1 F1 L1 M1 Q0 V1 X4 Y0 SPEED=38400 PARITY=N WORDLEN=8 DIAL=TONE OFF LINE &A3 &B1 &C1 &D2 &H1 &I0 &K1 &M4 &N0 &R2 &S0 &T5 &U0 &Y1 S00=000 S01=000 S02=043 S03=013 S04=010 S05=008 S06=004 S07=045 S08=002 S09=006 S10=014 S11=070 S12=050 S13=000 S15=000 S16=000 S18=000 S19=000 S21=010 S22=017 S23=019 S25=005 S27=001 S28=008 S29=020 S30=000 S31=128 S32=002 S33=000 S34=000 S35=000 S36=014 S38=000 S39=011 S40=000 S41=004 S42=000 LAST DIALLED #: OK The speed agrees with the status bar in minicom which shows 38400 8N1. Use 'CTRL-A Z P' to get to minicom comm parameters and set them to 115200 8N1 From this point on I only show the top few lines of the status as the other fields did not change when the speed was changed. Get current status from modem using ati 4 which gives: U.S. Robotics 56K Voice EXT Settings... B0 E1 F1 L1 M1 Q0 V1 X4 Y0 SPEED=115200 PARITY=N WORDLEN=8 ... The speed has increased to 115200 as per settings in minicom and it agrees with the minicom status line. Switched off modem and rebooted PC into kernel 2.4.26-gentoo-r12. Switch on modem. Run minicom Get current status from modem using ati 4 which gives: U.S. Robotics 56K Voice EXT Settings... B0 E1 F1 L1 M1 Q0 V1 X4 Y0 SPEED=9600 PARITY=N WORDLEN=8 ... Speed from modem is reported as 9600 but status line at base of minicom shows 38400 8N1. (How am I getting data back from the modem if the speeds are different?) Use 'CTRL-A Z P' to get to minicom comm parameters and set them to 115200 8N1 Get current status from modem using ati 4 which gives: U.S. Robotics 56K Voice EXT Settings... B0 E1 F1 L1 M1 Q0 V1 X4 Y0 SPEED=9600 PARITY=N WORDLEN=8 ... minicom now indicates speed as 115200 8N1 while modem still shows 9600. I tried setting minicom to 9600, did ati 4 and, as expected, got the 9600 speed from the modem. I then switched minicom back up to 115200. The modem still reported 9600. Just out of interest, I set minicom to 300 8N1 and the modem still reported 9600. It looks like your suspicions were correct. The comm speed is staying at 9600 regardless of the setting in minicom (and, presumably, any other software that is using the modem). But why? Switched back to kernel 2.4.26-gentoo-r9 and all is fine again. I do not have 2.4.26-gentoo-r10 on my PC but I believe that the change occurred in that release as that is when I first noticed this problem.
Why do you not use a 2.6 kernel? 2.6 is faster, better, nicer and overall will give you more speed for example I noticed that on my p166/32MB ram the nfs speed got up from 1 to 4.5Mb/sec It will also probably solve your issue ;) Did you try with 2.4.28? (better take 2.6 if you intend it) Please switch to 2.6, that makes it really easier to track such problems: http://www.gentoo.org/doc/en/kernel-upgrade.xml
I think that patch in -r10 is causing it: try: cd /usr/portage/distfiles wget http://dev.gentoo.org/~plasmaroo/patches/kernel/misc/security/gentoo-sources-2.4.22-CAN-2004-0814.patch cd /usr/src/linux patch -p1 -R < /usr/portage/distfiles/gentoo-sources-2.4.22-CAN-2004-0814.patch
Changed owner of this bug to kernel.
I am not using a 2.6 kernel because I thought that I would stick with what the Gentoo kernel team concider to be stable. I believe that the 2.6 series is still installed using emerge gentoo-dev which suggets to me that it is still regarded as a development kernel. I am looking to set up a file and terminal server using an old p200/256MB ram. I may try out the 2.6 kernel on that while there is still nothing of consequence on it. I built 2.4.26-gentoo-r13 to try it out and it still had the problem. I ran the command suggested against 2.4.26-gentoo-r13 to remove the contents of the patch performed by gentoo-sources-2.4.22-CAN-2004-0814.patch, and rebuilt the kernel. It now works fine. The message from the modem after connect reads CONNECT 44000/ARQ/V90/LAPM/V42BIS It looks like you found the patch that added the 'fixed speed' feature to the kernel serial port driver :-). Just out of interest, is a variation of this patch not also run against the 2.6 series? I would hate to install 2.6 on my proposed file and terminal server only to find that the terminals will only run at 9600. Thanks for the pointers. Mark
I cannot really check that, but you really should install a 2.6.9 kernel, also to be able to report the problem, if it is still in there.
I have downloaded and installed 2.6.9-gentoo-r6. The serial port seems to be working fine and the modem reported connect as: CONNECT 44000/ARQ/V90/LAPM/V42BIS I will try a vanilla 2.4.28 install and report back...
The vanilla 2.4.28 kernel worked fine also.
If its working fine on recent kernels then we are all happy :)
I have been playing with the 2.6.9 kernel since the Gentoo weekly news mentioned that it was now considered stable enough. It does seem to be working much better for me than the last 2.6 kernel I tried, and I think that I will stick with it. I am not sure how this will affect this bug report though, as the bug is still there in the 2.4 series. I will just say however, that whatever was done to cause the problem, please do not do it to the the 2.6 series :-). Mark
*** Bug 76605 has been marked as a duplicate of this bug. ***
I consider this bug as not fixed, after all still all of our 2.4 gentoo-sources are broken, so this bug will be in a default gentoo install with these kernels. The patch that is causing it: http://dev.gentoo.org/~plasmaroo/patches/kernel/misc/security/gentoo-sources-2.4.22-CAN-2004-0814.patch I dont know what it is for, but maybe we can remove it. Maybe someone knowing more could comment?
Mind trying gentoo-sources-2.4.28...?
Please reopen when you reply to comment #17
