<span style="font-family: Tahoma, Geneva, sans-serif; font-size: 10pt"><br>Support does appear to be present but there is a problem returning back to user space I suspect.<br><br>What fails is it causes Linux user space programs to get Segmentation errors.<br>Issuing a simple ls causes a segmentation fault sometimes. The shell gets terminated <br>and you cannot log back in. INIT: Id "T0" respawning too fast: disabled for 5 minutes pops up.<br><br>However, the critical interrupt handler keeps running. I know this by adding the reading <br>of a physical I/O location in the handler and can see it is being read on the scope.<br><br><br>The only code in the handler is below.<br><br>void critintr_handler(void *dev)<br>{<br> critintrcount++; // increment a variable<br> iodata = *piom; // read an I/O location <br> mtdcr(0x0c0, 0x00002000); // clear critical interrupt<br>}<br><br><br>Below is a log of the type of crashes that occur:<br><br>root@10.34.9.213:/opt/ppmac/ktest# ls<br>
Segmentation fault<br>
root@10.34.9.213:/opt/ppmac/ktest# ls<br>Segmentation fault<br>root@10.34.9.213:/opt/ppmac/ktest# ls<br>Makefile ktest.c ktest.ko ktest.mod.o modules.order<br>Module.symvers ktest.cbp ktest.mod.c ktest.o<br>root@10.34.9.213:/opt/ppmac/ktest# ls<br><br>Debian GNU/Linux 7 powerpmac ttyS0<br><br>powerpmac login: root<br><br>Debian GNU/Linux 7 powerpmac ttyS0<br><br>powerpmac login: root<br><br>Debian GNU/Linux 7 powerpmac ttyS0<br><br>powerpmac login: root<br><br>Debian GNU/Linux 7 powerpmac ttyS0<br><br>powerpmac login: root<br>Password: <br>Last login: Thu Nov 30 20:42:16 UTC 1933 on ttyS0<br>Linux powerpmac 3.2.21-aspen_2.01.09 #10 Mon Aug 19 08:49:12 PDT 2013 ppc<br><br>The programs included with the Debian GNU/Linux system are free software;<br>the exact distribution terms for each program are described in the<br>individual files in /usr/share/doc/*/copyright.<br><br>Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent<br>permitted by applicable law.<br>INIT: Id "T0" respawning too fast: disabled for 5 minutes<br><br><span style="font-family: tahoma,arial,sans-serif; font-size: 10pt;"><hr size="2" width="100%" align="center"><b>From</b>: "Benjamin Herrenschmidt" <benh@kernel.crashing.org><br><b>Sent</b>: Saturday, August 17, 2013 3:05 PM<br><b>To</b>: "Kumar Gala" <galak@kernel.crashing.org><br><b>Cc</b>: linuxppc-dev@lists.ozlabs.org, hbausley@deltatau.com<br><b>Subject</b>: Re: Critical Interrupt Input</span><br><br>On Fri, 2013-08-16 at 06:04 -0500, Kumar Gala wrote:<br>> The 44x low level code needs to handle exception stacks properly for<br>> this to work. Since its possible to have a critical exception occur<br>> while in a normal exception level, you have to have proper saving of<br>> additional register state and a stack frame for the critical<br>> exception, etc. I'm not sure if that was ever done for 44x.<br><br>Don't 44x and FSL BookE share the same macros ? I would think 44x does<br>indeed implement the same crit support as e500...<br><br>What does the crash look like ?<br><br>Ben.<br><br><br>_______________________________________________<br>Linuxppc-dev mailing list<br>Linuxppc-dev@lists.ozlabs.org<br>https://lists.ozlabs.org/listinfo/linuxppc-dev<br><br></span>
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