Re: [PATCH v2] serial: samsung: fix serial console break

[Peter Hurley <peter@hurleysoftware.com>]

On 04/17/2015 02:43 AM, Robert Baldyga wrote:
> This patch fixes problems with serial console break. When function
> s3c64xx_serial_startup() was started while serial console has been working,
> it caused lose of characters written to TX FIFO. This effect was particularly
> observable with systemd, which closes serial port every time when it's
> not currently needed, hence function s3c64xx_serial_startup() is called
> quite often there. To fix this problem we avoid resetting TX FIFO if port is
> used as serial console.
> 
> Example of broken console log:
> 
> [ 1086.7         Expecting device dev-ttySAC1.device...
> [ 1086.[  OK  ] Reached target Paths.
> [ 1086.756416] s[  OK  ] Reached target Swap.
> [ 1086.776413] systemd[1]: Reached target Swap.
> [ 1086.776642] systemd[1]: Starting Root Slice.
> [    5.53403[  OK  ] Created slice Root Slice.
> [    5.548433] systemd[1]: Create[  OK  ] Created slice User and Session Slice.
> [    5.568414] sys[  OK  ] Listening on /dev/initctl Compatibility Named Pipe.
> [    5.588388] s[  OK  ] Listening on Delayed Shutdown Socket.
> [    5.608376] sy[  OK  ] Listening on Journal Socket (/dev/log).
> [    5.628361] [  OK  ] Listening on udev Kernel Socket.
> [    5.648357] s[  OK  ] Listening on udev Control Socket.
> [    5.668353] s[  OK  ] Listening on Journal Socket.
> [    5.688366] systemd[1]: Listeni[  OK  ] Created slice System Slice.
> [    5.708393]          Mounting Temporary Directory...
> [ 7139.067436]          Starting prepare device daemon...
> [ 7139.091726] sy         Starting Generate environment from /etc/profile.d...
> [    5.792867] system         Starting Create Static Device Nodes in /dev...
> [ 7848.718         Mounting Debug File System...
> [ 7848.7384         Mounting Configuration File System...
> [    5.852         Starting Apply Kernel Variables...
> [    5.8720         Starting Setup Virtual Console...
> [ 7848.798         Starting udev Coldplug all Devices...
> [ 7848.817         Starting Journal Service...
> [  OK  ] Started Journal Service.
> [ 7848.854222] s[  OK  ] Reached target Slices.
>          Starting Remount Root and Kernel File Systems...
> [  OK  ] Mounted Configuration File System.

Reviewed-by: Peter Hurley <peter@hurleysoftware.com>