The J721E QoS table (arch/arm/mach-k3/r5/j721e/j721e_qos_uboot.c) gives the DSS read channels order-ID 15, but CONFIG_K3_QOS defaults to y only for AM62A, and unlike j721e_evm_r5_defconfig the BeagleBone AI-64 R5 defconfig does not enable it. The DSS QoS registers are left at 0, so the display competes with VPAC/C7x traffic at the same priority and underflows under vision load.
Measured on a BeagleBone AI-64 (J721E SR2.0), Linux 6.18, live IMX219 -> VPAC ISP -> TIDL on C7x for 25 s with 1080p DP output active: without this change tidss reports 40-41 "SYNC LOST / underflow" events per run (3 runs); with it all 24 DSS QoS registers are programmed by R5 SPL and there are none (2 runs). Signed-off-by: bslette <[email protected]> --- configs/j721e_beagleboneai64_r5_defconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/configs/j721e_beagleboneai64_r5_defconfig b/configs/j721e_beagleboneai64_r5_defconfig index d45f610d1..ef08fb374 100644 --- a/configs/j721e_beagleboneai64_r5_defconfig +++ b/configs/j721e_beagleboneai64_r5_defconfig @@ -4,6 +4,7 @@ CONFIG_SYS_MALLOC_F_LEN=0x70000 CONFIG_SPL_GPIO=y CONFIG_SPL_LIBCOMMON_SUPPORT=y CONFIG_SOC_K3_J721E=y +CONFIG_K3_QOS=y CONFIG_K3_EARLY_CONS=y CONFIG_TARGET_J721E_R5_BEAGLEBONEAI64=y CONFIG_HAS_CUSTOM_SYS_INIT_SP_ADDR=y -- 2.47.3
