On Tue, Jan 31, 2023 at 07:14:40AM +0100, Sascha Hauer wrote: > On Tue, Jan 31, 2023 at 05:42:29AM +1100, John Watts wrote: > > On Mon, Jan 30, 2023 at 05:36:58PM +0100, Sascha Hauer wrote: > > > You can't disable MMU during runtime, but you can compile without MMU > > > support, just disable CONFIG_MMU. However, the early I2C code already > > > runs with MMU disabled, can't you just put in some test code there? > > > > This is going to sound really silly but I'm not sure how to time the code > > without a clock. I guess grabserial? > > You could udelay(10000000) and measure the time with a stopwatch. > That should be accurate enough for this purpose already, in the end > the time will differ anyway between SoCs. > > If you want to measure more exactly we have this little perl script > which prints a timestamp for each line printed. Right I shall try this- though I do wonder if this is a lost cause if the bus clock changes in future i.MX chips. Unless this is specific to the I2C clock. But I was under the assumption the registers aren't dependent on the clock. > Sascha John.
