uterm: video_fbdev: discard non-xrgb32 devices

We discard all non-xrgb32 devices for simplicity reasons for now. We
definitely need to support other devices in future but that makes the
backend unnecessarily complex at the beginning so avoid it.

This also moves the resolution-change to the beginning and duplicates the
tests so we can be totally sure that everything is right after setting the
correct values.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>

diff --git a/src/uterm_video_fbdev.c b/src/uterm_video_fbdev.c
index e3323c7..4d7f3e6 100644 (file)
--- a/src/uterm_video_fbdev.c
+++ b/src/uterm_video_fbdev.c
@@ -108,6 +108,33 @@ static int display_activate_force(struct uterm_display *disp,
        finfo = &disp->fbdev.finfo;
        vinfo = &disp->fbdev.vinfo;
 
+       vinfo->xoffset = 0;
+       vinfo->yoffset = 0;
+       vinfo->activate = FB_ACTIVATE_NOW | FB_ACTIVATE_FORCE;
+       vinfo->xres_virtual = vinfo->xres;
+       vinfo->yres_virtual = vinfo->yres * 2;
+       vinfo->bits_per_pixel = 32;
+
+       log_info("activating display %s to %ux%u %u bpp", disp->fbdev.node,
+                vinfo->xres, vinfo->yres, vinfo->bits_per_pixel);
+
+       ret = ioctl(disp->fbdev.fd, FBIOPUT_VSCREENINFO, vinfo);
+       if (ret) {
+               log_err("video_fbdev: cannot set vinfo (%d): %m", errno);
+               return -EFAULT;
+       }
+
+       if (vinfo->yres_virtual < vinfo->yres * 2 ||
+           vinfo->xres_virtual < vinfo->xres) {
+               log_error("device %s does no double-buffering",
+                         disp->fbdev.node);
+               return -EFAULT;
+       }
+
+       ret = refresh_info(disp);
+       if (ret)
+               return ret;
+
        /* We require TRUECOLOR mode here. That is, each pixel has a color value
         * that is split into rgba values that we can set directly. Other visual
         * modes like pseudocolor or direct-color do not provide this. As I have
@@ -132,25 +159,13 @@ static int display_activate_force(struct uterm_display *disp,
                }
        }
 
-       vinfo->xoffset = 0;
-       vinfo->yoffset = 0;
-       vinfo->activate = FB_ACTIVATE_NOW | FB_ACTIVATE_FORCE;
-       vinfo->xres_virtual = vinfo->xres;
-       vinfo->yres_virtual = vinfo->yres * 2;
-
-       log_info("activating display %s to %ux%u", disp->fbdev.node,
-                vinfo->xres, vinfo->yres);
-
-       ret = ioctl(disp->fbdev.fd, FBIOPUT_VSCREENINFO, vinfo);
-       if (ret) {
-               log_err("video_fbdev: cannot set vinfo (%d): %m", errno);
+       if (vinfo->yres_virtual < vinfo->yres * 2 ||
+           vinfo->xres_virtual < vinfo->xres) {
+               log_error("device %s does no double-buffering",
+                         disp->fbdev.node);
                return -EFAULT;
        }
 
-       ret = refresh_info(disp);
-       if (ret)
-               return ret;
-
        if (finfo->visual != FB_VISUAL_TRUECOLOR ||
            vinfo->bits_per_pixel < 16) {
                log_error("device %s does not support true-color bpp >= 16",
@@ -158,9 +173,15 @@ static int display_activate_force(struct uterm_display *disp,
                return -EFAULT;
        }
 
-       if (vinfo->yres_virtual < vinfo->yres * 2 ||
-           vinfo->xres_virtual < vinfo->xres) {
-               log_error("device %s does not double-buffering",
+       /* TODO: remove this check and correctly provide conversions for the
+        * blitting functions. In fact, the for-loop above is totally useless
+        * while using this restriction here but lets be optimistic and say that
+        * this will be replaced soon. */
+       if (vinfo->red.offset != 16 || vinfo->red.length != 8 ||
+           vinfo->green.offset != 8 || vinfo->green.length != 8 ||
+           vinfo->blue.offset != 0 || vinfo->green.length != 8 ||
+           vinfo->bits_per_pixel != 32) {
+               log_error("device %s does not support xrgb32",
                          disp->fbdev.node);
                return -EFAULT;
        }