On Fri, Sep 21, 2007 at 08:20:13PM -0700, Steve Graham wrote: > I've just recently fixed this problem on my E9000 core which is a MSP85XX. I > did some digging and found that the problem started to occur in 2.6.16 and > is not there in 2.6.15. I looked into the deltas and found the specific > change that broke me. The file is c-r4k.c. > > In the function "local_r4k_flush_cache_sigtramp" there is a conditional: > > if (!cpu_icache_snoops_remote_store && scache_size) > protected_writeback_scache_line(addr & ~(sc_lsize - 1)); > > This additional "scache_size" has been added to this conditional. On my > platform, "scache_size" is set to zero so the > "protected_writeback_scache_line" is now not being called. I took out the > "scache_size" from the conditional and now I boot without any illegal > instructions. In this case the question is, why is scache_size 0 on your platform? I suppose that's because sc-rm7k.c has it's own scache_size so c-r4k.c never gets to see the right value so maybe the sanest fix would be to move sc-rm7k.c into c-r4k.c. > As a side note, I also took out the workaround in "war.h". This workaround > only hid the problem, it didn't fix it. Before I changed the conditional, I > would crash on every boot without the workaround. The workaround reduced > the crashes to maybe 1 in 3. Now, without the workaround, and with the > change in the conditional, I haven't experienced any problems. > > I'm sure this change was made for a reason in 2.6.16 so I'm not sure what > the official fix needs to be but that solved my issues on my platform. ICACHE_REFILLS_WORKAROUND_WAR is a separate issue - you need to enable it for all RM7000 and also unless PMC changed mind also all E9000 cores. So while I can understand that disabling this for testing a fix for the real issue you definately should reenable this once you're done. > Let me know if there is anything anyone wants me to try on my platform to > help come to an official fix for this problem. I wrote most of that stuff anyway ... Ralf
