i965: call intel_prepare_render always when reading pixels

Currently we do this only in the fallback code (when tiled memcpy
version failed) but it needs to be done always so that we have
correct read and write buffer in place. No regressions seen in CI.

Fixes:
	dEQP-EGL.functional.buffer_age.*

Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98330
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Chad Versace <chadversary@chromium.org>
diff --git a/src/mesa/drivers/dri/i965/intel_pixel_read.c b/src/mesa/drivers/dri/i965/intel_pixel_read.c
index c15f891..2563897 100644
--- a/src/mesa/drivers/dri/i965/intel_pixel_read.c
+++ b/src/mesa/drivers/dri/i965/intel_pixel_read.c
@@ -242,17 +242,17 @@
       perf_debug("%s: fallback to CPU mapping in PBO case\n", __func__);
    }
 
-   ok = intel_readpixels_tiled_memcpy(ctx, x, y, width, height,
-                                      format, type, pixels, pack);
-   if(ok)
-      return;
-
-   /* glReadPixels() wont dirty the front buffer, so reset the dirty
+   /* Reading pixels wont dirty the front buffer, so reset the dirty
     * flag after calling intel_prepare_render(). */
    dirty = brw->front_buffer_dirty;
    intel_prepare_render(brw);
    brw->front_buffer_dirty = dirty;
 
+   ok = intel_readpixels_tiled_memcpy(ctx, x, y, width, height,
+                                      format, type, pixels, pack);
+   if(ok)
+      return;
+
    /* Update Mesa state before calling _mesa_readpixels().
     * XXX this may not be needed since ReadPixels no longer uses the
     * span code.