Messages in this thread | | | Date | Wed, 06 May 2009 15:51:14 -0500 | From | Jason Wessel <> | Subject | Re: [PATCH 5/5] usb_debug: EXPERIMENTAL - poll hcd device to forcewrites |
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Greg KH wrote: >> Doing enough printk's such as in register_console() will cause loss >> because you run out of URBs unless you can force them to complete. >> > > Why not just make the upper bound of urbs very large? We used to have > an unlimited number of in-flight urbs for some drivers until it was > pointed out that a simple: > cat /dev/null > /dev/ttyUSB0 > would cause a DoS :) > > What happens if your upper bound is 400? 4000? Will that work > properly? > Sure, if you have enough of a urb available, ultimately you get all the printk's.
If I want to printk from the nmi_watchdog out to this device, am I going to get anything if the write is not synchronous, because in theory the hcd device is never going to get accessed again?
Ideally I want to make sure that somehow I get my debug output out to the console, even if it means we do some polling after the oops state is set.
Jason.
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