Re: [Sound-open-firmware] [PATCH] [RFC]platform: calculate the percentage of cpu cycle

On Thu, 2018-06-21 at 12:04 +0200, Lauda, Tomasz wrote:

Hi Zhigang,

I think, that correct value for 400MHz clock is:

*#define CPU_CYCLE_PER_MS 400000000*

Tomek **

On 21.06.2018 11:59, zhigangw wrote:

...

I use this way to calculate the CPU usage in our firmware.

I am not sure this way is correct or not.

from this way, I found the percentage is very high when I only do the playback alone with tdm8 mode.

almost 95% CPU usage.

that is the reason I send this RFC.

please give me the feedback whether this way to calculate the CPU usage is correct or not.

This is broken, you are just timing DMA interrupts. Please enable verbose trace and you should see all the calls time stamped.

Liam