From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <3AB63E12.6D38973E@esd-electronics.com> Date: Mon, 19 Mar 2001 18:12:50 +0100 From: Matthias Fuchs MIME-Version: 1.0 To: linuxppc-embedded Subject: losing interrupts - printk is bad Content-Type: text/plain; charset=iso-8859-1 Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Hi, I got a nice problem: I am working on an embedded PPC board (IBM405CR) with a serial console (115200 baud). While I was testing some new driver code, I made a lot of prink debugging output - as we all like to do :-) My problem is, that I always lose some bytes on an other serial port. I found out that printk waits until the complete format string is send through the console. That takes about 5 ms for 40 bytes. During this time printk blocks the interrupts !!! That means some incomming data on the other serial port can be (and is) lost. This is a very strange problem. Well first would be glad to get a good workaround. Well, a 'klogd -c 1' turn off all the debuggin and printk is much faster, but I need the debugging output. Second, could anybody explain t ome, what klogd is doing ? It would be glad to get klogd read all the debugging output from the kernel and output the data from user space (well buffered and not blocking the whole system). It seems that klogd cannot do that, am I right ? Matthias -- ------------------------------------------------- \ Matthias Fuchs \ \ esd electronic system design Gmbh \ \ Vahrenwalder Straße 205 \ \ D-30165 Hannover \ \ email: matthias.fuchs@esd-electronics.com \ \ phone: +49-511-37298-0 \ \ fax: +49-511-37298-68 \ -------------------------------------------------- ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/