Send jobs to an unplugged usb printer on linux increases cpu usage

[michaelrsweet]

Version: 1.3.6
CUPS.org User: salem

If you send a job to an unplugged usb printer on linux, the process called usb takes 100% of cpu usage.
It happens, as far as I can see, due to an infinite loop in usb-unix.c.
If no device returns EBUSY, sleep() is never called.
The attached patch fixes this issue here. Please, check if it can be applied upstream and if there are no side-effects.

Thank you

[michaelrsweet]

CUPS.org User: mike

Fixed in Subversion repository.

[michaelrsweet]

"cups-1.3.6-disconnected-usb-increases-cpu-usage.patch":

diff -p -up cups-1.3.6/backend/usb-unix.c.org cups-1.3.6/backend/usb-unix.c
--- cups-1.3.6/backend/usb-unix.c.org 2008-03-25 10:39:46.000000000 -0300
+++ cups-1.3.6/backend/usb-unix.c 2008-03-25 10:40:20.000000000 -0300
@@ -417,8 +417,8 @@ open_device(const char uri, / I - Dev
{
_cupsLangPuts(stderr,
_("INFO: Printer busy; will retry in 5 seconds...\n"));

• sleep(5);
  }

•  sleep(5);
  

  }
  }
  #elif defined(__sun) && defined(ECPPIOC_GETDEVID)