On Monday 29 June 2009 18:07:44 Russell King - ARM Linux wrote: > On Mon, Jun 29, 2009 at 05:35:37PM +0200, Jean Pihet wrote: > > On Monday 29 June 2009 17:19:31 Russell King - ARM Linux wrote: > > > It's one of these things that nests itself - when you have several IRQs > > > being processed on one CPU, there are several register contexts saved, > > > and get_irq_regs() returns the most recent one. > > > > > > > The use case is that the performance unit (PMNC) of the Cortex A8 has > > > > some serious bug, in short the performance counters overflow IRQ is > > > > to be avoided. > > > > > > I don't follow. None of the PMNC support code in the mainline kernel > > > uses get_irq_regs() outside of IRQ context. > > > > That is correct. The Cortex A8 needs some special treatment. > > The errata says that if the counters are overflowing at the same time as > > a coprocessor access is performed, the perf unit gets reset and/or locks > > up. In short the counters overflow is to be avoided and so the PMNC IRQ. > > Are you talking about 628216? Yes that is the one. Sorry not to mention it sooner. Jean -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
