Accessing CEMODE to change A78AE split-lock mode on Nvidia Orin

Hi,

I am trying to change “CEMODE” so i can use “Split-Lock” defined here:
https://developer.arm.com/documentation/101779/0001/Functional-description/Split-Lock-feature/Implementing-Split-Lock

I am struggling to find where and how to change this boot option so i can change the split-lock mode. Would you know if its possible and if so, how?

Cheers,

Joe

hello user163011,

you may have a try to modify this file, $OUT/Linux_for_Tegra/bootloader/tegra234-mb1-bct-misc-common.dtsi
please update the ccplex_platform_features as 0x1 to enable hybrid mode;
i.e. ccplex_platform_features = <0x1 0x00000000> for all hybrid.
you’ll need to modify num_clusters_2core_pair_lockstep to enable lock mode, the value is the number of clusters present in the system.
i.e. ccplex_platform_features = <0x0 0x00000000> && num_clusters_2core_pair_lockstep = <0x3> for all lockstep.

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Hi, I have changed the value to:
ccplex_platform_features = <0x0 0x00000000>
num_clusters_2core_pair_lockstep = <0x3>

But after it boots it fails with this error message:

▒debugfs initialized
▒▒ERROR:   **************************************
ERROR:   RAS Uncorrectable Error in CCPMU, base=0xe001000:
ERROR:          Status = 0xe4000504
ERROR:   SERR = Assertion failure: 0x4
ERROR:          IERR = uCode Error: 0x5
ERROR:          MISC0 = 0x10
ERROR:          MISC1 = 0x0
ERROR:          MISC2 = 0x0
ERROR:          MISC3 = 0x0
ERROR:          ADDR = 0x60a5a5a5a5a5a5a5
ERROR:   **************************************
ERROR:   *d*i*d*s*at*h_*v*n* **t**n*d**1*******
ERROR:   RAS Uncorrectable Error in CCPMU, base=0xe001000:
ERROR:          Status = 0xec000504
ERROR:   SERR = Assertion failure: 0x4
ERROR:          IERR = uCode Error: 0x5
ERROR:          Overflow (there may be more errors) - Uncorrectable
ERROR:          MISC0 = 0x10
ERROR:          MISC1 = 0x0
ERROR:          MISC2 = 0x0
ERROR:          MISC3 = 0x0
ERROR:          ADDR = 0x60a5a5a5a5a5a5a5
ERROR:   **************************************
ERROR:   sdei_dispatch_event returned -1

Would you know how to fix this?
Also do you have any documentation on setting these values to set the A78AE to lock mode, split mode and hybrid mode

hello user163011,

FYI, we’re able to repo the same failure locally.
we have arrange resources for checking this. will update this thread after issue resolve.

Booting standard/default L4T in lock/hybrid mode is not supported.
Please disable the ‘C7’ cpuidle state by setting “min-residency-us” property to ‘0xFFFFFFFF’ in the below DT node to boot in lock/hybrid mode.

    cpus{
            cpu_core_power_states {
                    c7 {
                            ....
                            min-residency-us = <0xFFFFFFFF>;
                            ....
                    };
            };
    }
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