From bed76caa6caaea6a6598755b82a54425a9d9f73e Mon Sep 17 00:00:00 2001
From: Keith Packard <keithp@guitar.keithp.com>
Date: Mon, 5 Mar 2007 23:36:00 -0800
Subject: [PATCH] Use EDID data to set screen physical size at server startup.

Screen physical size is set to a random value before the RandR code gets
control, override that and reset it to a value based on the compat_output
physical size (if available). If that output has no physical size, just use
96dpi as the default resolution and set the physical size as appropriate.
(cherry picked from commit 843077f23a1b49bd712d931421753e3a09d4008c)
---
 hw/xfree86/modes/xf86RandR12.c | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/hw/xfree86/modes/xf86RandR12.c b/hw/xfree86/modes/xf86RandR12.c
index 052d12aa3..ce780b6ef 100644
--- a/hw/xfree86/modes/xf86RandR12.c
+++ b/hw/xfree86/modes/xf86RandR12.c
@@ -422,8 +422,28 @@ xf86RandR12CreateScreenResources (ScreenPtr pScreen)
 	}
 	else
 	{
-	    mmWidth = pScreen->mmWidth;
-	    mmHeight = pScreen->mmHeight;
+	    xf86OutputPtr   output = config->output[config->compat_output];
+	    xf86CrtcPtr	    crtc = output->crtc;
+
+	    if (crtc && crtc->mode.HDisplay &&
+		output->mm_width && output->mm_height)
+	    {
+		/*
+		 * If the output has a mode and a declared size, use that
+		 * to scale the screen size
+		 */
+		DisplayModePtr	mode = &crtc->mode;
+		mmWidth = output->mm_width * width / mode->HDisplay;
+		mmHeight = output->mm_height * height / mode->VDisplay;
+	    }
+	    else
+	    {
+		/*
+		 * Otherwise, just set the screen to 96dpi
+		 */
+		mmWidth = width * 25.4 / 96;
+		mmHeight = height * 25.4 / 96;
+	    }
 	}
 	xf86DrvMsg(pScrn->scrnIndex, X_INFO,
 		   "Setting screen physical size to %d x %d\n",