Hi Stephen, On 12/01/2016 05:04 PM, Stephen Warren wrote: > On 12/01/2016 07:15 AM, Ralf Ramsauer wrote: >> Hi, >> >> I observed that touching MMIO regions of Tegra devices with its >> corresponding clock gate deactivated immediately freezes the whole >> system. No kernel panic, nothing. >> >> I tested this behavior with a small kernel module, find it attached. A >> few seconds after loading this module, the whole device freezes. Tested >> this on a TK1 and TX1. > > Unfortunately, this is indeed the way the HW works. That's no good news :( Do you know if this applies to the whole Tegra architecture or only to some boards? > >> What is the actual expected behavior on ARM(64) when touching ungated >> MMIO regions? Is it specified somewhere? > > I don't believe the ARM architecture specifies behaviour in this case, > or if it does, defines it as implementation defined, which means that > pretty much any behaviour is valid. I tested the same scenario on another ARM64 board (LeMaker HiKey), which did (fortunately) not freeze. Ralf -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html