[PATCH] compositor-fbdev: Wait and retry before failing on reconnect to the framebuffer

[nerdopolis]

Resolving https://bugs.freedesktop.org/show_bug.cgi?id=73782
udev might be configured to set the permissions on framebuffer devices with the UACCESS attribute.
Weston currently attempts to reconnect to the framebuffer device before udev can set the permissions back.

It waits 3 times in case if the system is heavily paging, or slowed down, and prevents udev from working.
In my testing the delay is long enough where it works on the first try
---
 src/compositor-fbdev.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/compositor-fbdev.c b/src/compositor-fbdev.c
index 7c505ce..42d2881 100644
--- a/src/compositor-fbdev.c
+++ b/src/compositor-fbdev.c
@@ -663,13 +663,23 @@ fbdev_output_reenable(struct fbdev_compositor *compositor,
 	struct fbdev_output *output = to_fbdev_output(base);
 	struct fbdev_screeninfo new_screen_info;
 	int fb_fd;
+	int retries;
 	const char *device;
 
 	weston_log("Re-enabling fbdev output.\n");
 
 	/* Create the frame buffer. */
-	fb_fd = fbdev_frame_buffer_open(output, output->device,
+	fb_fd = -1;
+	retries = 0;
+	while (fb_fd < 0 && retries < 3) {
+		usleep(10000);
+		fb_fd = fbdev_frame_buffer_open(output, output->device,
 	                                &new_screen_info);
+		if (fb_fd < 0) {
+		  weston_log("Creating frame buffer failed. Retrying...\n");
+		}
+		retries++;
+	}
 	if (fb_fd < 0) {
 		weston_log("Creating frame buffer failed.\n");
 		goto err;
-- 
2.1.0