Re: Patch to allow TSC with APM
On 18-Apr-00 Poul-Henning Kamp wrote: It would be nice to have some kind of understanding why the tsc is better than the i8254 before we kludge it... Unless I misread completely one nice side effect of this would be to enable pcaudio on APM machines. To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
Re: Patch to allow TSC with APM
Hi, I'd like to recommend the following patches. Adding the option "CLK_USE_TSC_ANYWAY" allows my laptop to use the TSC even though it is "flakey". This option should not be set by default. I saw the same kind of patches and my laptop has this w/o any problems for long time. I'd like to commit submitted patch 2 or 3 days later if no objections. Thanks To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
Re: Patch to allow TSC with APM
In message [EMAIL PROTECTED], Mitsuru IWASAKI writes : Hi, I'd like to recommend the following patches. Adding the option "CLK_USE_TSC_ANYWAY" allows my laptop to use the TSC even though it is "flakey". This option should not be set by default. I saw the same kind of patches and my laptop has this w/o any problems for long time. I'd like to commit submitted patch 2 or 3 days later if no objections. It would be nice to have some kind of understanding why the tsc is better than the i8254 before we kludge it... -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD coreteam member | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
Re: Patch to allow TSC with APM
Out of the ether, Poul-Henning Kamp spewed forth the following bitstream: I'd like to recommend the following patches. Adding the option "CLK_USE_TSC_ANYWAY" allows my laptop to use the TSC even though it is "flakey". This option should not be set by default. I saw the same kind of patches and my laptop has this w/o any problems for long time. I'd like to commit submitted patch 2 or 3 days later if no objections. It would be nice to have some kind of understanding why the tsc is better than the i8254 before we kludge it... Any ideas on what would be needed to go forward with that? AlanC -- \ Alan B. Clegg Just because I can\ [EMAIL PROTECTED] does not mean I will. \ http://www.firehouse.net/ \ To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
Re: Patch to allow TSC with APM
In message [EMAIL PROTECTED], Alan Clegg writes: Out of the ether, Poul-Henning Kamp spewed forth the following bitstream: I'd like to recommend the following patches. Adding the option "CLK_USE_TSC_ANYWAY" allows my laptop to use the TSC even though it is "flakey". This option should not be set by default. I saw the same kind of patches and my laptop has this w/o any problems for long time. I'd like to commit submitted patch 2 or 3 days later if no objections. It would be nice to have some kind of understanding why the tsc is better than the i8254 before we kludge it... Any ideas on what would be needed to go forward with that? If the offset is systematic, maybe we should do more to calibrate the i8254 against the RTC, say a 10 second period instead of just one sec (can be done in the back-ground). If it is because the bios fiddles the frequency all the time we should maybe understand the APM bios better. If it is because SMI interrupts "steal" time from us, then the TSC is maybe better. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD coreteam member | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
Re: Patch to allow TSC with APM
In message [EMAIL PROTECTED] Poul-Henning Kamp writes: : If it is because the bios fiddles the frequency all the time we : should maybe understand the APM bios better. There were issues with some APM BIOSes not resetting this on resume, but I think that we properly store/restore the state now. : If it is because SMI interrupts "steal" time from us, then the : TSC is maybe better. This is an excellent theory since the problems are on newer laptops that use SMI a whole lot. But 6 seconds a minute is way too large to account for this unless the SMI interrupts are timed really really poorly. On a high precision system we have here that needs to run off the i8245, we've found that interrupts at the wrong time can cause "dropouts" of 1 click of time. Since these dropouts happen only once in 1000 samples and are eliminated by the outlier elimination mechanisms that we have in the software, I've not investigated this further. I guess what I'm saying is that this might be possible, but I don't know for sure if it is or not. Warner To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
