diff options
Diffstat (limited to 'drivers/tty/hvc/Kconfig')
-rw-r--r-- | drivers/tty/hvc/Kconfig | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/drivers/tty/hvc/Kconfig b/drivers/tty/hvc/Kconfig index 6a3c97d345a0..4f9264d005c0 100644 --- a/drivers/tty/hvc/Kconfig +++ b/drivers/tty/hvc/Kconfig @@ -1,5 +1,4 @@ # SPDX-License-Identifier: GPL-2.0 -if TTY config HVC_DRIVER bool @@ -82,14 +81,34 @@ config HVC_DCC bool "ARM JTAG DCC console" depends on ARM || ARM64 select HVC_DRIVER + select SERIAL_CORE_CONSOLE help This console uses the JTAG DCC on ARM to create a console under the HVC 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 + depends on RISCV_SBI_V01 select HVC_DRIVER help This enables support for console output via RISC-V SBI calls, which @@ -113,5 +132,3 @@ config HVCS will depend on arch specific APIs exported from hvcserver.ko which will also be compiled when this driver is built as a module. - -endif # TTY |