--- cups-1.2.10/backend/runloop.c.usb-paperout	2006-12-06 20:10:16.000000000 +0000

+++ cups-1.2.10/backend/runloop.c	2007-05-29 19:21:32.000000000 +0100

@@ -40,6 +40,14 @@

 #endif /* __hpux */

+#ifdef __linux

+#include <sys/ioctl.h>

+#include <linux/lp.h>

+#include <time.h>

+int linux_usb_paperout_hack = 0;

+#endif /* __linux */

+

+

 /*

  * 'backendRunLoop()' - Read and write print and back-channel data.

  */

@@ -64,6 +72,9 @@

 #if defined(HAVE_SIGACTION) && !defined(HAVE_SIGSET)

   struct sigaction action;		/* Actions for POSIX signals */

 #endif /* HAVE_SIGACTION && !HAVE_SIGSET */

+#ifdef __linux

+  time_t	last_write = 0;		/* Last time write() succeeded */

+#endif /* __linux */

   fprintf(stderr, "DEBUG: backendRunLoop(print_fd=%d, device_fd=%d, use_bc=%d)\n",

@@ -110,12 +121,9 @@

     FD_ZERO(&input);

     if (!print_bytes)

       FD_SET(print_fd, &input);

-    if (use_bc)

-      FD_SET(device_fd, &input);

     FD_ZERO(&output);

-    if (print_bytes || !use_bc)

-      FD_SET(device_fd, &output);

+    FD_SET(device_fd, &output);

     if (use_bc)

     {

@@ -141,14 +149,24 @@

     * Check if we have back-channel data ready...

     */

-    if (FD_ISSET(device_fd, &input))

+    if (use_bc && FD_ISSET(device_fd, &output)) /* finished writing */

     {

-      if ((bc_bytes = read(device_fd, bc_buffer, sizeof(bc_buffer))) > 0)

+      struct timeval nowait;

+      fd_set readback;

+      FD_ZERO (&readback);

+      nowait.tv_sec = 0;

+      nowait.tv_usec = 0;

+      FD_SET(device_fd, &readback);

+      if (select (device_fd + 1, &readback, NULL, NULL, &nowait) &&

+	  FD_ISSET(device_fd, &readback))

       {

-	fprintf(stderr,

-	        "DEBUG: Received " CUPS_LLFMT " bytes of back-channel data!\n",

-	        CUPS_LLCAST bc_bytes);

-        cupsBackChannelWrite(bc_buffer, bc_bytes, 1.0);

+	if ((bc_bytes = read(device_fd, bc_buffer, sizeof(bc_buffer))) > 0)

+	{

+	  fprintf(stderr,

+		  "DEBUG: Received " CUPS_LLFMT " bytes of back-channel data!\n",

+		  CUPS_LLCAST bc_bytes);

+	  cupsBackChannelWrite(bc_buffer, bc_bytes, 1.0);

+	}

       }

     }

@@ -227,6 +245,9 @@

       }

       else

       {

+#ifdef __linux

+	last_write = time (NULL);

+#endif /* __linux */

         if (paperout)

 	{

 	  fputs("STATE: -media-empty-error\n", stderr);

@@ -247,7 +268,42 @@

 	total_bytes += bytes;

       }

     }

+

+#ifdef __linux

+    if (linux_usb_paperout_hack)

+    {

+      time_t now;

+      if (!paperout &&

+	  ((now = time(NULL)) - last_write) > 5)

+      {

+	unsigned int status;

+	if (ioctl (device_fd, LPGETSTATUS, &status) == 0 &&

+	    (status & LP_POUTPA))

+	{

+	  fputs("ERROR: Out of paper!\n", stderr);

+	  fputs("STATE: +media-empty-error\n", stderr);

+	  paperout = 1;

+	}

+

+	/* Don't check status for another 5s. */

+	last_write = now;

+      }

+    }

+#endif /* __linux */

+  }

+

+#ifdef __linux

+  if (linux_usb_paperout_hack)

+  {

+    /* Wait for the last write() to finish. */

+    do

+    {

+      FD_ZERO(&output);

+      FD_SET(device_fd, &output);

+    } while (select(device_fd + 1, NULL, &output, NULL, NULL) < 0 &&

+	     errno == EINTR);

   }

+#endif /* __linux */

  /*

   * Return with success...

--- cups-1.2.10/backend/usb-unix.c.usb-paperout	2007-05-29 19:10:08.000000000 +0100

+++ cups-1.2.10/backend/usb-unix.c	2007-05-29 19:10:08.000000000 +0100

@@ -39,6 +39,11 @@

 #include "ieee1284.c"

 #include <sys/select.h>

+#ifdef __linux

+#include <unistd.h>

+#include <fcntl.h>

+extern int linux_usb_paperout_hack;

+#endif /* __linux */

 /*

  * Local functions...

@@ -70,6 +75,11 @@

   (void)argc;

   (void)argv;

+#ifdef __linux

+  /* Get the runloop to check for USB paper-out condition. */

+  linux_usb_paperout_hack = 1;

+#endif /* __linux */

+

  /*

   * Open the USB port device...

   */

@@ -150,6 +160,12 @@

   tcsetattr(device_fd, TCSANOW, &opts);

+#ifdef __linux

+  /* Put the file descriptor into non-blocking mode so that we

+   * get a chance to detect paper-out. */

+  fcntl (device_fd, F_SETFL, fcntl (device_fd, F_GETFL) | O_NONBLOCK);

+#endif /* __linux */

+

  /*

   * Finally, send the print file...

   */