[RFC PATCH 0/5] earlycon hang under some conditions
From: Jeffy Chen
Date: Tue Jul 18 2017 - 00:30:19 EST
I was testing earlycon with 8250 dw serial console. And it hangs in
these cases:
1/ kernel hang when calling early write function after free_initmem:
a) the earlycon not disabled after the init code(due to keep_bootcon or
not specify a real console to switch to)
b) the early write func is marked as __init, for example 8250_early.
2/ kernel hang when calling early write function after disable unused
clks/pm domain:
a) the earlycon not disabled after the init code
b) the disable unused clks/pm domain kill the requiered clks/pm
domain, since they are not referenced by the earlycon.
3/ kernel hang when calling early write function after the serial
console driver runtime suspended:
a) the earlycon not disabled after the init code
b) the serial console driver's runtime suspend kills the requiered
clks/pm domain, since they are not referenced by the earlycon.
This serial fix 1/ case only.
Jeffy Chen (5):
serial: arc: Remove __init marking from early write
serial: omap: Remove __init marking from early write
serial: xuartps: Remove __init marking from early write
serial: 8250_ingenic: Remove __init marking from early write
serial: 8250_early: Remove __init marking from early write
drivers/tty/serial/8250/8250_early.c | 8 ++++----
drivers/tty/serial/8250/8250_ingenic.c | 8 ++++----
drivers/tty/serial/arc_uart.c | 4 ++--
drivers/tty/serial/omap-serial.c | 13 ++++++-------
drivers/tty/serial/xilinx_uartps.c | 2 +-
5 files changed, 17 insertions(+), 18 deletions(-)
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2.1.4