Date: Sat, 10 May 2014 09:51:09 +0200 From: Hans Petter Selasky <hps@selasky.org> To: Ian Lepore <ian@FreeBSD.org> Cc: "freebsd-arm@freebsd.org" <freebsd-arm@FreeBSD.org> Subject: Re: USB isochronous traffic with Rasberry Pi [WAS: Re: USB audio device on Raspberry Pi] Message-ID: <536DDA6D.7060101@selasky.org> In-Reply-To: <1399661378.22079.376.camel@revolution.hippie.lan> References: <20140425154430.GA76168@utility-01.thismonkey.com> <535A8AEA.1000100@selasky.org> <20140425204134.GA458@cicely7.cicely.de> <20140430091411.GA45015@utility-01.thismonkey.com> <5360C0A7.9010407@selasky.org> <1398867266.22079.51.camel@revolution.hippie.lan> <CAGW5k5bZ_bTQUXuzNm=tbwx3npz1_HoOR3vM8TBRVFs8zWCq-w@mail.gmail.com> <5362638B.1080104@selasky.org> <5363C133.2000304@selasky.org> <53677CB8.5000800@selasky.org> <CAJ-Vmo=XmH-RX6_i13NuAXhq-jTC%2BWedGiyOMJaPO4r014DSgw@mail.gmail.com> <1399303695.22079.239.camel@revolution.hippie.lan> <1399304157.22079.243.camel@revolution.hippie.lan> <CAJ-Vmok-%2B7%2Bcq%2BDa6_C2AA7BuP5readY_Gfwwm_RF5kh4VerQA@mail.gmail.com> <5368A93D.3070608@selasky.org> <5368AC03.8080401@selasky.org> <536CE5E9.8020408@selasky.org> <1399647986.22079.367.camel@revolution.hippie.lan> <536D0575.1040407@selasky.org> <1399661378.22079.376.camel@revolution.hippie.lan>
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Hi, I've made one more patch to the DWC OTG driver. Nice if you can test that too. http://svnweb.freebsd.org/changeset/base/265806 BTW: I think I've found what is causing the glitches when using USB audio devices: diff --git a/sys/arm/arm/machdep.c b/sys/arm/arm/machdep.c index 0490be7..de7f015 100644 --- a/sys/arm/arm/machdep.c +++ b/sys/arm/arm/machdep.c @@ -423,7 +423,7 @@ cpu_est_clockrate(int cpu_id, uint64_t *rate) void cpu_idle(int busy) { - +#if 0 CTR2(KTR_SPARE2, "cpu_idle(%d) at %d", busy, curcpu); #ifndef NO_EVENTTIMERS @@ -442,6 +442,7 @@ cpu_idle(int busy) #endif CTR2(KTR_SPARE2, "cpu_idle(%d) at %d done", busy, curcpu); +#endif } int It appears that cpu_idle() is going to sleep when there are pending interrupts, and then waking up on the next timer IRQ! Can someone familiar with these parts of the kernel comment? Please try for yourself, with and without the patch above, using an USB audio device with the RPI-B! Still when the console is printing, there are significant glitches too :-) That's because the TTY layer is synchronously writing data to the serial line. That's OK for now. --HPS
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