On 12/04/2013 10:35 AM, Meelis Roos wrote:
There were some changes to sunsab.c a couple of versions ago; maybe we
broke it.
Can you confirm BRKs are being received with
'sudo cat /proc/tty/driver/serial'
In 3.12:
# cat /proc/tty/driver/sunsab
serinfo:1.0 driver revision:
0: uart:SAB82532 V3.2 mmio:0x1FFF1400000 irq:5 tx:5163 rx:0 CTS|DSR|CD
1: uart:SAB82532 V3.2 mmio:0x1FFF1400040 irq:5 tx:0 rx:
cat /proc/sys/kernel/stop-a
1
# cat /proc/sys/kernel/reboot-cmd
(it was empty, so default "boot" should be used AFAIK)
Meelis,
Would you please re-test trying to break to the PROM with this debug
patch? As with the bootpromfs debug patch, the output is in
'/sys/kernel/debug/trace'.
Should I activate tracing somehow?
You did activate tracing. The lack of output means at that point
there is no BRK detected. Can you trigger any sysrq function from
that terminal (assuming CONFIG_SERIAL_SUNSAB_CONSOLE && CONFIG_MAGIC_SYSRQ)?
I can not trigger SysRq by sending a break and then immediately s (or t
also tested). Nothing in trace. Magic SysRq is 0x1 like default in
kernel conf. This in on the SUNSAB Ultra5 machine.
That's what I thought: just wanted to validate.
Not sure why no BRK is detected (isr1 & ISR1_BRK == 0). Maybe there is
an early-out that is ignoring BRK condition. Or the sunsab driver is not
reading/interpreting the correct register/bits.
You could instrument the irq handler, sunsab_interrupt(), with trace_printk()
to see if BRK is ever detected.
E3500 with zs serial console has working break but I do now know how to
send SysRq there - Break drops me to prom prompt, I can "go" there but
anything after that is inteprreted as normal input.
I'm not sure how BRK is intended to be used for both the PROM console
and SysRq on a serial console. If you temporarily disable the PROM console,
the SysRq should work by typing a SysRq command char after sending a break.
[ FWIW, Minicom's break function sends a lot of BRKs because it's designed
to trigger a modem interrupt. AFAIK there isn't a 'single-char length
break' supported by minicom. ]
How shoyukd SysRq
over verial console work - have not used it before?
The first input after a BRK is interpreted as a SysRq command (within 5 secs).
Regards,
Peter Hurley
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