On Wednesday 12 January 2005 2:30 pm, Kent Forschmiedt wrote: > It helps if you do this: > > echo 0 >/proc/sys/kernel/printk > tail -f /proc/kmsg >
Not for all problems. Like if you're chasing a system lockup, you really _need_ to know the last few events, and "tail" is never going to show them. Also, remember that that this level of development the hardware may be extremely uncooperative (especially pxa25x!!) and that you may be concerned with particular code paths as they affect hardware races (like "how long does it take this signal to latch into that register"). Even the cost of printk-to-memory can be more than enough to force code to hit (or miss) a race. - Dave > -----Original Message----- > From: David Brownell [mailto:[EMAIL PROTECTED] > Sent: Wednesday, January 12, 2005 2:24 PM > To: linux-usb-devel@lists.sourceforge.net > Cc: Alan Stern; Vladimir Trukhin > Subject: Re: [linux-usb-devel] g_file_storage and Windows - problem in > connection on pxa255 > > ... > > That is, putting long debug printks into that driver will regularly > cause things to break ... for a variety of hard-to-describe reasons. > > It's very possible that some of the failures being seen here are > happening only because of these excessively long debug messages. > > If you absolutely must use printks to debug IRQ paths in that > driver, get used to messages that encode all the important stuff > in single characters ... or, in special cases, a few more. And > even then, be prepared to watch the driver change behavior very > significantly when you remove one of those printks... > > ... ------------------------------------------------------- The SF.Net email is sponsored by: Beat the post-holiday blues Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek. It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
