diff options
Diffstat (limited to 'drivers/tty/hvc/Kconfig')
| -rw-r--r-- | drivers/tty/hvc/Kconfig | 27 |
1 files changed, 24 insertions, 3 deletions
diff --git a/drivers/tty/hvc/Kconfig b/drivers/tty/hvc/Kconfig index 8d60e0ff67b4..c2a4e88b328f 100644 --- a/drivers/tty/hvc/Kconfig +++ b/drivers/tty/hvc/Kconfig @@ -87,15 +87,36 @@ 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 + depends on RISCV_SBI && NONPORTABLE select HVC_DRIVER help This enables support for console output via RISC-V SBI calls, which - is normally used only during boot to output printk. + is normally used only during boot to output printk. This driver + conflicts with real console drivers and should not be enabled on + systems that directly access the console. - If you don't know what do to here, say Y. + If you don't know what do to here, say N. config HVCS tristate "IBM Hypervisor Virtual Console Server support" |