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

From: Peter Hurley
Date: Sat Apr 18 2015 - 10:43:03 EST


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@xxxxxxxxxxxxxxxxxx>


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