xf86-video-intel: src/i830.h

[Carl Worth]

 src/i830.h |    7 +++++++
 1 file changed, 7 insertions(+)

New commits:
commit d24010b7b3f2419beb40dc5ae1e8aeb3e04b5a93
Author: Carl Worth <cworth at cworth.org>
Date:   Thu Oct 9 14:29:04 2008 -0700

    Disable frame buffer compression by default for GM965.
    
    We haven't found a way to make FBC work reliably with GM965 yet,
    (it often fails to notice CPU writes). This appears to be a
    specific problem with this device, (as we haven't gotten similar
    bug reports for subsequent devices such as GM45). So FBC is
    now disabled by default for GM965 but can still be enabled with
    the FrameBufferCompression option for experimenting/debugging.
    
    This resolves bug #16257:
    
    	[GM965 EXA] Frame-buffer compression broken for CPU writes (XPutImage)
    	https://bugs.freedesktop.org/show_bug.cgi?id=16257

diff --git a/src/i830.h b/src/i830.h
index 5b78236..89f19d2 100644
--- a/src/i830.h
+++ b/src/i830.h
@@ -950,6 +950,13 @@ static inline int i830_fb_compression_supported(I830Ptr pI830)
      */
     if (!pI830->tiling || (IS_I965G(pI830) && pI830->accel <= ACCEL_XAA))
 	return FALSE;
+    /* We have not gotten FBC to work consistently on 965GM. Our best
+     * working theory right now is that FBC simply isn't reliable on
+     * that device. See this bug report for more details:
+     * https://bugs.freedesktop.org/show_bug.cgi?id=16257
+     */
+    if (IS_I965GM(pI830))
+	return FALSE;
     return TRUE;
 }