Re: [PATCH v1 0/3] console, serial8250: Disable PM and DMA ops

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Tue, 2018-05-15 at 21:34 +0300, Andy Shevchenko wrote:
> Kernel console is sensitive to any kind of complex work needed to
> print
> out anything on it. One such case is emergency print during Oops.
> 
> This series proposes to disable runtime PM and DMA operations on 8250
> serial console.
> 
> More detailed explanation why is provided in patch 2.
> 
> The series has been in our internal trees for years already with no
> problems observed.

+Cc: Tony.

You might have some thoughts / test means for this.

> 
> Andy Shevchenko (3):
>   console: introduce ->exit() callback
>   serial: 8250_port: Don't use power management for kernel console
>   serial: 8250_port: Disable DMA operations for kernel console
> 
>  drivers/tty/serial/8250/8250_core.c |  9 +++++++++
>  drivers/tty/serial/8250/8250_port.c | 27 ++++++++++++++++++++++-----
>  include/linux/console.h             |  1 +
>  include/linux/serial_8250.h         |  1 +
>  kernel/printk/printk.c              |  3 +++
>  5 files changed, 36 insertions(+), 5 deletions(-)
> 

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy