On 04/26/2012 12:39 PM, Philippe Gerum wrote: > On 04/12/2012 05:57 PM, Philippe Gerum wrote: >> On 04/12/2012 05:45 PM, Michael Pustylnik wrote: >>> The code masking the interrupt in IPIC (call for >>> ipipe_pre_cascade_noeoi()) initially showed up in the patch you >>> recommended (see your email attached). >>> >>> Later on it was integrated in Xenomai commit >>> "9a5e42df8bccc59620c08caeb4b9fe92dbf94a1b". >>> >>> As shown in the trail below, it keeps interrupts all the time until the >>> scheduler returns, thus breaking real-time responsiveness. >>> >>> A solution to this is probably to remove calling >>> ipipe_pre_cascade_noeoi() and let the cascading handler mask the >>> interrupt. Am I missing something? Do you think it is safe to use this >>> solution? >> >> No, as interrupts could be re-enabled before invoking the handler, you >> would get an IRQ storm. >> >> The solution is to rework the cascaded IRQ handling in the generic >> pipeline core, so that all decoded IRQs are acked/masked, then the >> multiplex IRQ unmasked, then all the decoded IRQ handlers fired when >> syncing the relevant pipeline stage. >> >> A fix for this will follow when enough testing will have been done on >> arm and ppc, to check whether that logic does not raise other issue. >> > > This is the patch series fixing the issue in the newest pipeline "core" > implementation, currently for kernel 3.2. Something along these lines would > work for > earlier kernels as well. > > http://git.denx.de/?p=ipipe-2.6.git;a=commit;h=0a9a7b4e4ce9f4196a574471ad58f4389820c438 > http://git.denx.de/?p=ipipe-2.6.git;a=commit;h=f2ca3c2baf58bf43f4c00fb05b91b16da9fd77f2 > http://git.denx.de/?p=ipipe-2.6.git;a=commit;h=a4b909ccf80c5afa132aa7a9ccf0022cb8a6e6f2 > http://git.denx.de/?p=ipipe-2.6.git;a=commit;h=b47bc773ff07ce886aaf490921ac59e98ed9575a
I have done a backport of this change for a pre ipipe-core (ARM) I-pipe. The diff is here: http://git.xenomai.org/?p=ipipe-gch.git;a=commitdiff;h=81bfc05c4716b76e79f5e486baf4c52015a3b92c;hp=7d31a77f62acb57eb83409c8f514d0f2dacf7fe5 -- Gilles. _______________________________________________ Xenomai-help mailing list Xenomai-help@gna.org https://mail.gna.org/listinfo/xenomai-help
