I have a design that I'm including the adrv9009/zcu102 reference design 2018.3. I noticed that the axi_clk from the zynqmp pl0 changes from 99.99 to 103.42 MHz when linux boots. I tested this by querying the clock rate before (while in uboot) and after the os boots. I also confirmed this when launching a standalone application through sdk. Can someone tell me where the OS is changing the pl0 clock rate? Thanks!
So, if you are using 2018.3, I assume you are using this branch. What you are suggesting should work but it's should not be really necessary all of that. I would just extend the devicetree…
I found in the boot messages that SI570 MGT Frequency is being changed. I had initially set it to 153.6 MHZ in the ZCU102 Board Interface GUI
[5.245592] si570 10-005d: registered, current frequency 148500000 Hz
Can someone tell me why it's Si570 is being reprogrammed?
Okay I've found that people have had this issue before:
Can someone tell me if there is any zcu102/adrv9009 functionality that depends on the Si570 MGT Frequency being 148.5 MHz?
Can someone tell me how to remove programming of the 148.5 MHz clk from boot up/device tree? I've been looking at the device tree and system-top.dts and cannot find any mention of 148500000. Thanks!
Here is the 148.5M. You can play with it as described on the Xilinx forum in the link you posted above.
mmedrano said:Can someone tell me if there is any zcu102/adrv9009 functionality that depends on the Si570 MGT Frequency being 148.5 MHz?
You also might find the answer to this question on a Xilinx forum.
Thanks for this! But, I've been using petalinux to build (https://wiki.analog.com/resources/tools-software/linux-build/generic/petalinux).
The petalinux-config uses meta-adi (https://github.com/analogdevicesinc/meta-adi.git) to import /analogdevicesinc/linux. I don't have a lot of experience with these things.. Would a good fix be to create a new branch in /analogdevicesinc/linux/ that doesn't program the Si570 and then set that branch to KBRANCH = new_branch in (https://github.com/analogdevicesinc/meta-adi/blob/master/meta-adi-xilinx/recipes-kernel/linux/linux-xlnx_%25.bbappend)? Thanks!