Oooh...it gets worse... I hadn't previously had CONFIG_PREEMPT_RT defined in kernel config...tried it, rebuilt...but, I get this message when I try to rebuild dsp/bios link
drv_pmgr.c:146:2: #error Realtime preemption is not supported with this version of DSP/BIOS Link Is that CONFIG_PREEMPT_RT necessary (default is CONFIG_PREEMPT_DESKTOP) to get sub 10ms resolution for usleep and select blocks, etc.??? Randy -----Original Message----- From: Roberts, Randy Sent: Friday, October 16, 2009 11:04 AM To: 'Steve Chen' Cc: davinci-linux-open-source@linux.davincidsp.com Subject: RE: jiffie resolution and usleep accuracy Hi Steve, I haven't applied any additional patches to the stock MV 2.6.10 release [r...@flir ~]# cat /proc/version Linux version 2.6.10_mvl401-davinci_evm-PSP_01_30_00_082 (gcc version 3.4.3 (MontaVista 3.4.3-25.0.104.0600975 2006-07-06)) #1 Fri Oct 16 10:29:49 PDT 2009 I noticed a CONFIG_PREEMPT_RT patch on the linux wiki...is that what you're referring to? How can I start using the CONFIG_PREEMPT_RT patch? Please see the RT PREEMPT HOWTO for a detailed description. The short version is to get the latest -rt patch from http://www.kernel.org/pub/linux/kernel/projects/rt/, then get the related vanilla kernel from http://kernel.org, apply the patch to the kernel, configure, and compile the kernel. Has this patch been successfully applied to MVs Davinci 2.6.10? From http://rt.wiki.kernel.org/index.php/CONFIG_PREEMPT_RT_Patch#Platforms_Te sted_and_in_Use_with_CONFIG_PREEMPT_RT It looks like it has been applied to OMAP 5912 and DM6446 Davinci, but it does mention 2.6.23rt specifically... Thanks for the assist, Randy -----Original Message----- From: Steve Chen [mailto:sc...@mvista.com] Sent: Friday, October 16, 2009 10:55 AM To: Roberts, Randy Cc: davinci-linux-open-source@linux.davincidsp.com Subject: Re: jiffie resolution and usleep accuracy On Fri, 2009-10-16 at 10:15 -0700, Roberts, Randy wrote: > Running 2.6.10 on a DM6467 I see usleep having a minimum resolution of > 10ms.. > > For DM6467, and other ARM Davinci linux implementations, 2.6.10 based > specifically, how does one get the jiffies to 1ms, instead of what > appears to be 10ms? > > I believe I have HIGHRES timers enabled... > > Anything else one needs to do to get usleep resolution 1ms instead of > 10ms? > > Scheduler config? > What is the patch level? DM6467 HRT was not working correct. There was a patch that fixed the problem. Regards, Steve _______________________________________________ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
