hosted: Minor corrections to the linux framebuffer driver.

 * Query variable info _before_ mmaping the framebuffer
 * Sanity-check the resolution/bitdepth, and if it doens't match
   try to set it to what we want.

This is functionally a no-op.

Change-Id: I087ff81775d8f63bf7846b7fef19f6fc36c1cc84

1 files changed, 13 insertions, 11 deletions

diff --git a/firmware/target/hosted/lcd-linuxfb.c b/firmware/target/hosted/lcd-linuxfb.c
index 14c8c30f89..5dda5cf1cc 100644
--- a/firmware/target/hosted/lcd-linuxfb.c
+++ b/firmware/target/hosted/lcd-linuxfb.c
@@ -59,14 +59,21 @@ void lcd_init_device(void)
         panicf("Cannot read framebuffer fixed information");
     }
 
-#if 0
-    /* check resolution and framebuffer size */
-    if(vinfo.xres != LCD_WIDTH || vinfo.yres != LCD_HEIGHT || vinfo.bits_per_pixel != LCD_DEPTH)
+    if(ioctl(fd, FBIOGET_VSCREENINFO, &vinfo) < 0)
     {
-        panicf("Unexpected framebuffer resolution: %dx%dx%d\n", vinfo.xres,
-            vinfo.yres, vinfo.bits_per_pixel);
+        panicf("Cannot read framebuffer variable information");
+    }
+
+    /* Make sure we match our desired bitdepth */
+    if (vinfo.bits_per_pixel != LCD_DEPTH || vinfo.xres != LCD_WIDTH || vinfo.yres != LCD_HEIGHT) {
+        vinfo.bits_per_pixel = LCD_DEPTH;
+        vinfo.xres = LCD_WIDTH;
+        vinfo.yres = LCD_HEIGHT;
+        if (ioctl(fd, FBIOPUT_VSCREENINFO, &vinfo)) {
+            panicf("Cannot set framebuffer to %dx%dx%d",
+               vinfo.xres, vinfo.yres, vinfo.bits_per_pixel);
+        }
     }
-#endif
     /* Note: we use a framebuffer size of width*height*bbp. We cannot trust the
      * values returned by the driver for line_length */
 
@@ -77,11 +84,6 @@ void lcd_init_device(void)
         panicf("Cannot map framebuffer");
     }
 
-    if(ioctl(fd, FBIOGET_VSCREENINFO, &vinfo) < 0)
-    {
-        panicf("Cannot read framebuffer variable information");
-    }
-
     memset(framebuffer, 0, finfo.smem_len);
 
 #ifdef HAVE_LCD_ENABLE