[PATCH] drm: Implement drmHandleEvent2()

[Tobias Jakobi]

Basically this is an extended version of drmHandleEvent().

drmHandleEvent() only handles core events (like e.g. page flips),
but since kernel DRM drivers might use vendor-specific events
to signal userspace the completion of pending jobs, etc., its
desirable to provide a way to handle these without putting
vendor-specific code in the core libdrm.

To use this you provide drmHandleEvent2() with a function that
handles your non-core events (and some opaque pointer).

The signature of that function looks like this:
void vendor(int fd, struct drm_event *e, void *custom_data);

'fd' is the DRM file descriptor, 'e' the non-core event, and
'custom_data' the aforementioned opaque pointer.

This way we don't have to maintain a copy of drmHandleEvent()
in the vendor code.

Signed-off-by: Tobias Jakobi <tjakobi at math.uni-bielefeld.de>
---
 xf86drm.h     | 13 +++++++++++++
 xf86drmMode.c | 10 +++++++++-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/xf86drm.h b/xf86drm.h
index 40c55c9..ad0ae1c 100644
--- a/xf86drm.h
+++ b/xf86drm.h
@@ -741,8 +741,21 @@ typedef struct _drmEventContext {
 
 } drmEventContext, *drmEventContextPtr;
 
+typedef void (*drmEventVendorHandler)(int fd, struct drm_event *e,
+	void *custom_data);
+
 extern int drmHandleEvent(int fd, drmEventContextPtr evctx);
 
+/*
+ * drmHandleEvent2() is an extended variant of drmHandleEvent() which
+ * allows handling of vendor-specific/non-core events.
+ * The function pointer 'vendorhandler' is used (if non-zero) to
+ * process non-core events. The opaque pointer 'data' is passed as
+ * the 'custom_data' argument.
+ */
+extern int drmHandleEvent2(int fd, drmEventContextPtr evctx,
+	drmEventVendorHandler vendorhandler, void *data);
+
 extern char *drmGetDeviceNameFromFd(int fd);
 extern int drmGetNodeTypeFromFd(int fd);
 
diff --git a/xf86drmMode.c b/xf86drmMode.c
index 1333da4..e68e3e2 100644
--- a/xf86drmMode.c
+++ b/xf86drmMode.c
@@ -857,7 +857,8 @@ int drmModeCrtcSetGamma(int fd, uint32_t crtc_id, uint32_t size,
 	return DRM_IOCTL(fd, DRM_IOCTL_MODE_SETGAMMA, &l);
 }
 
-int drmHandleEvent(int fd, drmEventContextPtr evctx)
+int drmHandleEvent2(int fd, drmEventContextPtr evctx,
+			drmEventVendorHandler vendorhandler, void *data)
 {
 	char buffer[1024];
 	int len, i;
@@ -900,6 +901,8 @@ int drmHandleEvent(int fd, drmEventContextPtr evctx)
 						 U642VOID (vblank->user_data));
 			break;
 		default:
+			if (vendorhandler)
+				vendorhandler(fd, e, data);
 			break;
 		}
 		i += e->length;
@@ -908,6 +911,11 @@ int drmHandleEvent(int fd, drmEventContextPtr evctx)
 	return 0;
 }
 
+int drmHandleEvent(int fd, drmEventContextPtr evctx)
+{
+	return drmHandleEvent2(fd, evctx, NULL, NULL);
+}
+
 int drmModePageFlip(int fd, uint32_t crtc_id, uint32_t fb_id,
 		    uint32_t flags, void *user_data)
 {
-- 
2.0.5