Add a poll function that alternates between zero and normal poll return to

bring DRM into conformance with normal poll().

linux-core/drmP.h

@@ -749,6 +749,7 @@ extern int drm_open_helper(struct inode *inode, struct file *filp,
 			   drm_device_t * dev);
 extern int drm_fasync(int fd, struct file *filp, int on);
 extern int drm_release(struct inode *inode, struct file *filp);
+unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait);
 
 				/* Mapping support (drm_vm.h) */
 extern void drm_vm_open(struct vm_area_struct *vma);

linux-core/drm_fops.c

@@ -451,3 +451,19 @@ int drm_release(struct inode *inode, struct file *filp)
 	return retcode;
 }
 EXPORT_SYMBOL(drm_release);
+
+/** No-op. */
+/* This is to deal with older X servers that believe 0 means data is
+ * available which is not the correct return for a poll function.
+ * By alternating returns both interfaces are happy. This is fixed
+ * in newer X servers.
+ */
+unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
+{
+	static int flip;
+	if ((flip = !flip))
+		return (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM);
+	return 0;
+}
+EXPORT_SYMBOL(drm_poll);
+

linux-core/ffb_drv.c

@@ -324,6 +324,7 @@ static struct drm_driver ffb_driver = {
 		.ioctl	 = drm_ioctl,
 		.mmap	 = drm_mmap,
 		.fasync  = drm_fasync,
+		.poll    = drm_poll,
 		.get_unmapped_area = ffb_get_unmapped_area,
 	},
 };

linux-core/i810_drv.c

@@ -114,6 +114,7 @@ static struct drm_driver driver = {
 		.release = drm_release,
 		.ioctl = drm_ioctl,
 		.mmap = i810_mmap_buffers,
+		.poll = drm_poll,
 		.fasync = drm_fasync,
 		},
 	.pci_driver = {

linux-core/i830_drv.c

@@ -124,6 +124,7 @@ static struct drm_driver driver = {
 		.release = drm_release,
 		.ioctl = drm_ioctl,
 		.mmap = i830_mmap_buffers,
+		.poll = drm_poll,
 		.fasync = drm_fasync,
 		},
 	.pci_driver = {

linux-core/i915_drv.c

@@ -89,6 +89,7 @@ static struct drm_driver driver = {
 		.release = drm_release,
 		.ioctl = drm_ioctl,
 		.mmap = drm_mmap,
+		.poll = drm_poll,
 		.fasync = drm_fasync,
 		},
 	.pci_driver = {

linux-core/mach64_drv.c

@@ -106,6 +106,7 @@ static struct drm_driver driver = {
 		.release = drm_release,
 		.ioctl = drm_ioctl,
 		.mmap = drm_mmap,
+		.poll = drm_poll,
 		.fasync = drm_fasync,
 		},
 	.pci_driver = {

linux-core/mga_drv.c

@@ -111,6 +111,7 @@ static struct drm_driver driver = {
 		.release = drm_release,
 		.ioctl = drm_ioctl,
 		.mmap = drm_mmap,
+		.poll = drm_poll,
 		.fasync = drm_fasync,
 		},
 	.pci_driver = {

linux-core/r128_drv.c

@@ -121,6 +121,7 @@ static struct drm_driver driver = {
 		.release = drm_release,
 		.ioctl = drm_ioctl,
 		.mmap = drm_mmap,
+		.poll = drm_poll,
 		.fasync = drm_fasync,
 		},
 	.pci_driver = {

linux-core/radeon_drv.c

@@ -161,6 +161,7 @@ static struct drm_driver driver = {
 		.release = drm_release,
 		.ioctl = drm_ioctl,
 		.mmap = drm_mmap,
+		.poll = drm_poll,
 		.fasync = drm_fasync,
 		},
 	.pci_driver = {

linux-core/savage_drv.c

@@ -299,6 +299,7 @@ static struct drm_driver driver = {
 		.release = drm_release,
 		.ioctl	 = drm_ioctl,
 		.mmap	 = drm_mmap,
+		.poll = drm_poll,
 		.fasync  = drm_fasync,
 	},
 	.pci_driver = {

linux-core/sis_drv.c

@@ -88,6 +88,7 @@ static struct drm_driver driver = {
 		.release = drm_release,
 		.ioctl = drm_ioctl,
 		.mmap = drm_mmap,
+		.poll = drm_poll,
 		.fasync = drm_fasync,
 		},
 	.pci_driver = {

linux-core/tdfx_drv.c

@@ -79,6 +79,7 @@ static struct drm_driver driver = {
 		.release = drm_release,
 		.ioctl = drm_ioctl,
 		.mmap = drm_mmap,
+		.poll = drm_poll,
 		.fasync = drm_fasync,
 		},
 	.pci_driver = {