Hi,

On Mon, Jul 17, 2017 at 11:02 PM, Jeffy Chen [off-list ref] wrote:

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(-)

I looked through all 5 patches and they seem sane to me.  I didn't go
through and test them since Brian already tested the patches for the
one UART driver I'd have access to anyway.

As per my previous email, I don't see any need to solve all the
world'd problems with this patch series, plus the keep_bootcon seems
to be an experts / debugging type option and it seems sane if you need
to take care in using it.

So officially for the series (FWIW since I'm just an interested 3rd party):

Reviewed-by: Douglas Anderson <dianders@chromium.org>


-Doug