cups/cups-usb-paperout.patch

--- cups-1.3b1/backend/runloop.c.usb-paperout	2007-07-11 22:46:42.000000000 +0100
+++ cups-1.3b1/backend/runloop.c	2007-07-18 11:40:45.000000000 +0100
@@ -135,6 +135,14 @@
 }
 
 
+#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.
  */
@@ -161,6 +169,9 @@
 #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,
@@ -210,8 +221,6 @@
     FD_ZERO(&input);
     if (!print_bytes)
       FD_SET(print_fd, &input);
-    if (use_bc)
-      FD_SET(device_fd, &input);
     if (side_cb)
       FD_SET(CUPS_SC_FD, &input);
 
@@ -221,7 +230,10 @@
 
     if (use_bc || side_cb)
     {
-      if (select(nfds, &input, &output, NULL, NULL) < 0)
+      struct timeval fives;
+      fives.tv_sec = 5;
+      fives.tv_usec = 0;
+      if (select(nfds, &input, &output, NULL, &fives) < 0)
       {
        /*
 	* Pause printing to clear any pending errors...
@@ -256,14 +268,24 @@
     * 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);
+	}
       }
     }
 
@@ -334,6 +356,10 @@
 	    offline = 1;
 	  }
 	}
+	else if (linux_usb_paperout_hack && errno == EAGAIN)
+	{
+	  sleep (1);
+	}
 	else if (errno != EAGAIN && errno != EINTR && errno != ENOTTY)
 	{
 	  fprintf(stderr, _("ERROR: Unable to write print data: %s\n"),
@@ -343,6 +369,9 @@
       }
       else
       {
+#ifdef __linux
+	last_write = time (NULL);
+#endif /* __linux */
         if (paperout)
 	{
 	  fputs("STATE: -media-empty-error\n", stderr);
@@ -363,7 +392,42 @@
 	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-1.3b1/backend/usb-unix.c.usb-paperout	2007-07-18 11:39:32.000000000 +0100
+++ cups-1.3b1/backend/usb-unix.c	2007-07-18 11:39:32.000000000 +0100
@@ -31,6 +31,11 @@
 #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...
@@ -63,6 +68,11 @@
   (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...
   */
@@ -156,6 +166,12 @@
 
   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...
   */