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-rw-r--r--drivers/tty/hvc/Kconfig19
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/tty/hvc/Kconfig b/drivers/tty/hvc/Kconfig
index 8d60e0ff67b4..4f9264d005c0 100644
--- a/drivers/tty/hvc/Kconfig
+++ b/drivers/tty/hvc/Kconfig
@@ -87,6 +87,25 @@ config HVC_DCC
driver. This console is used through a JTAG only on ARM. If you don't have
a JTAG then you probably don't want this option.
+config HVC_DCC_SERIALIZE_SMP
+ bool "Use DCC only on CPU core 0"
+ depends on SMP && HVC_DCC
+ help
+ This is a DEBUG option to serialize all console input and output to CPU 0.
+ Some external debuggers, do not handle reads/writes from/to DCC on more
+ than one CPU core. Each core has its own DCC device registers, so when a
+ CPU core reads or writes from/to DCC, it only accesses its own DCC device.
+ Since kernel code can run on any CPU core, every time the kernel wants to
+ write to the console, it might write to a different DCC.
+
+ In SMP mode, external debuggers create multiple windows, and each window
+ shows the DCC output only from that core's DCC. The result is that
+ console output is either lost or scattered across windows.
+
+ Enable this option only if you are sure that you do not need features like
+ CPU hotplug to work. For example, during early chipset bringups without
+ debug serial console support. If unsure, say N.
+
config HVC_RISCV_SBI
bool "RISC-V SBI console support"
depends on RISCV_SBI_V01