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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">We are seeking realtime performance of an interrupt routine using an APM86290 (44x based CPU). We changed the interrupt so it is a Critical Interrupt to reduce jitter. We do have a substantial amount of code in the interrupt routine.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Is it inappropriate to use a critical interrupt in a generic fashion. We did something like what you see below.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:black">CRITICAL_EXCEPTION(0x0100, CriticalInput, unknown_exception)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:black">to<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:black">CRITICAL_EXCEPTION(0x0100, CriticalInput, CustomCritIntr)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:black">The code for the handler is large<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:black">void CustomCritIntr (void)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:black">{<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:black"> LargeAmountOfCode();<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New";color:black">}<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The code runs fine in a standard interrupt handler but periodically we are getting the following types of error when we use our code in the critical interrupt handler. Is this a result of our CustomCritIntr handler disturbing the TLB
handlers of Linux? I will add the interrupt is generated at a very high rate every ie. 15 usecs.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><b>Unable to handle kernel paging request for data at address 0xa47bb580<o:p></o:p></b></p>
<p class="MsoNormal"><b>Faulting instruction address: 0x80088154<o:p></o:p></b></p>
<p class="MsoNormal"><b>Oops: Kernel access of bad area, sig: 11 [#1]<o:p></o:p></b></p>
<p class="MsoNormal"><b>SMP NR_CPUS=2 APM862xx vB<o:p></o:p></b></p>
<p class="MsoNormal"><b>Modules linked in: usralgo(O) rtpmac(O) libppmac(O) ppmachw(O) ec_r8169(O) ec_master(O) [last unloaded: usralgo]<o:p></o:p></b></p>
<p class="MsoNormal"><b>NIP: 80088154 LR: 8006799c CTR: a4796538<o:p></o:p></b></p>
<p class="MsoNormal"><b>REGS: 806cad90 TRAP: 0300 Tainted: G O (3.2.21-powerpmac-smp)<o:p></o:p></b></p>
<p class="MsoNormal"><b>MSR: 00021000 <ME,CE> CR: 28dd4f88 XER: 00000000<o:p></o:p></b></p>
<p class="MsoNormal"><b>DEAR: a47bb580, ESR: 00000000<o:p></o:p></b></p>
<p class="MsoNormal"><b>TASK = 9e076d00[0] 'swapper/1' THREAD: 9e0ac000 CPU: 1<o:p></o:p></b></p>
<p class="MsoNormal"><b>GPR00: a47bb4d0 806cae40 9e076d00 00000000 00000000 80088154 fff2eaf7 806df200<o:p></o:p></b></p>
<p class="MsoNormal"><b>GPR08: 806c0090 80621840 806bc790 00021000 9e0ac260 fff2eaf7 30000000 ffffffe0<o:p></o:p></b></p>
<p class="MsoNormal"><b>GPR16: a47c0000 a47c0000 00000000 a47c0000 00000000 a47c0000 ffffffff 000030dd<o:p></o:p></b></p>
<p class="MsoNormal"><b>GPR24: a47c0000 a76891a8 a7688800 a76891a8 00000004 80088154 8066dec8 a47bb4cc<o:p></o:p></b></p>
<p class="MsoNormal"><o:p> </o:p></p>
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