On Mittwoch, 24. August 2016 15:47:38 CEST Mikko Perttunen wrote: > Your log indicates you're running on kernel v3.18. Cpufreq for Tegra124 > is only implemented starting from v4.3, so you'd need to upgrade. The log I pointed to was not mine and it was the wrong one, sorry. I am actually working with mainline 4.7. Here is a more recent one from kernelci.org showing the same behavior: https://storage.kernelci.org/next/next-20160822/arm-tegra_defconfig/lab-baylibre-seattle/boot-tegra124-jetson-tk1.html The 12 seconds they need to boot to user space are caused by the NFS rootfs. I am booting from eMMC and need about 8 seconds. From the hardware specification I would expect this to be less than 2 seconds. > > [ 7.035525] cpufreq: cpufreq_online: CPU0: Running at unlisted freq: > > 696000 KHz [ 7.042895] cpufreq: cpufreq_online: CPU0: Unlisted initial > > frequency changed to: 714000 KHz > > > > For me this looks like it is using the frequency set up by the u-boot boot > > loader. This might also explain why the kernel currently needs about 8 > > seconds to boot which seems to be way too much for a Cortex-A15 device. > > Yes, this is normal. The device boots up with the CPUs on the PLLX clock > that runs at 696MHz. Later the cpufreq driver will switch to another > clock (which, btw, does not have 696 MHz as an operating point so you > will continue to see this message even on newer kernels.) Ok, so the code that sets the clock frequency according to the device tree seems to be missing. To reduce the boot time of the T124, the easiest solution might be to set the clock frequency to maximum in the boot loader and then set up cpufreq to use the 'performance' governor? Thanks, Josef -- 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
