Russell King wrote:
On Tue, Feb 08, 2011 at 01:37:05PM +0000, Russell King wrote:
Note that it would be a _significant_ timing disturbance as
INTERRUPT_ENABLE_SOT_MASK corresponds to 0x8a, which will cause a
misaligned access to an IO address. That may result in the alignment
handler being invoked, which will be much longer than just a single
write:
root@vexpress:~# cat /proc/cpu/alignment
...
System: 217
...
Word: 217
...
That's after a few seconds of running minicom on the ftdi_sio port.
With the correct register having the correct value written (SOT_MASK
into the interrupt register) that pause I reported seems gone, and it
no longer causes alignment faults.
I've been thinking if you prefer to have the patch fixed or an udelay()
but this sounds like you want the patch fixed.
Sebastian
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