at91: input overruns question
arasv at magellan-technology.com
Wed Oct 27 23:14:19 EDT 2010
On 26 October 2010 17:19, Aras Vaichas <arasv at magellan-technology.com> wrote:
> I'm updating our production kernel to 188.8.131.52-rt29 for an at91rm9200.
> This is the newest version supported by RT.
> I've noticed that the age-old debug serial input overrun(s) issue has
> gotten far worse and I can no longer use the cursor keys at all. i.e.
> no history on serial console or vi.
> As the kernel version numbers have gone up, the problem seems to have
> gotten worse.
> Is there anything that I can do to make it a bit more usable?
> Any .config changes?
Configuration settings CONFIG_NO_HZ and CONFIG_HIGH_RES_TIMERS cause
the overrun(s) problems to get worse.
If I disable these two settings I still get overrun(s) but not quite
Can someone explain why these settings would cause the CPU to be
unable to process 2 serial characters in a row?
Something must be causing the DBGU serial receive interrupt to stall
for more than 86us in order to miss a complete 115200 baud serial
More information about the linux-arm-kernel