Merge branch 'master' of git://www.denx.de/git/u-boot-imx

[oweals/u-boot.git] / arch / arm / cpu / armv8 / fsl-layerscape / README.lsch3

diff --git a/arch/arm/cpu/armv8/fsl-layerscape/README.lsch3 b/arch/arm/cpu/armv8/fsl-layerscape/README.lsch3
index db9359dd33d5a5201df7d9309f4a182eece8fb47..f9323c1d289d999a88b30492c87963caaf5672d2 100644 (file)
--- a/arch/arm/cpu/armv8/fsl-layerscape/README.lsch3
+++ b/arch/arm/cpu/armv8/fsl-layerscape/README.lsch3
@@ -303,3 +303,23 @@ How to use commands :-
        => fsl_mc start aiop 0x580900000
        => setenv ethact DPMAC1@xgmii
        => fsl_mc apply dpl 580700000
+
+Errata A009635
+---------------
+If the core runs at higher than x3 speed of the platform, there is
+possiblity about sev instruction to getting missed by other cores.
+This is because of SoC Run Control block may not able to sample
+the EVENTI(Sev) signals.
+
+Workaround: Configure Run Control and EPU to periodically send out EVENTI signals to
+wake up A57 cores
+
+Errata workaround uses Env variable "a009635_interval_val". It uses decimal
+value.
+- Default value of env variable is platform clock (MHz)
+
+- User can modify default value by updating the env variable
+  setenv a009635_interval_val 600; saveenv;
+  It configure platform clock as 600 MHz
+
+- Env variable as 0 signifies no workaround