hello all-
I posted a while back that we were having some problems with our normal
linux kernel drivers. It appeared that there were some missed interrupt
problems which were solved by changing the isr in rt_com. The isr polls the
uart in a while loop (set to 4 loops) after an interrupt. Switching this to
1 loop (only polling the uart once) solved our problem. We haven't lost any
data across the port (yet) and we run it at 115200 baud. Maybe this issue
is related.
Troy Davis
Airborne Data Systems, Inc.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of
Stephen D. Cohen
Sent: Tuesday, December 04, 2001 8:54 AM
To: '[EMAIL PROTECTED]'
Subject: [rtl] RT_COM and CLI Query
Gang,
Can anyone tell me why the RT_COM code does hard CLI and push flags
calls to protect the buffer manipulation code? It does this not only in the
read and write routines (where some protection is necessary), but also in
the ISR (where no protection {other than that already afforded by being in
ISR context} should be required).
It would seem to me that the read and write routines could simply
block the associated IRQ with rtl_hard_disable_irq and rtl_hard_enable_irq.
Do these routines not pend interrupts or some such?
On the whole, it seems like a bad idea for the serial port handling
code to be turning off all interrupts for the system while it does its
thing. I am fairly sure the rt_com guys knew what they were doing, I just
don't understand why it was necessary.
Regards,
Steve
--------------------------
Stephen D. Cohen
Engineering Manager
Xybion Sensor Positioning Systems
11528 53rd Street North
Clearwater, FL 33760
Voice: (727) 299-0150
Fax: (727) 299-0804
[EMAIL PROTECTED]
www.xybion.com
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