[Intel-gfx] [PATCH 22/26] drm/i915: clarify that checking the FB stride for CFB is intentional

[Paulo Zanoni]

Daniel was looking at this code and asked about whether fb->pitches[0]
is correct, then he suggested we should a comment to make sure it is
actually intentional.

For more information on the CFB size calculation, please see the
commit message of:

commit c4ffd40908c30a33291227920e921f6b45b9e8f7
Author: Paulo Zanoni <paulo.r.zanoni at intel.com>
Date:   Thu Oct 1 19:55:57 2015 -0300
    drm/i915: fix CFB size calculation

Requested-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
---
 drivers/gpu/drm/i915/intel_fbc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
index 01807c5..4bb2323 100644
--- a/drivers/gpu/drm/i915/intel_fbc.c
+++ b/drivers/gpu/drm/i915/intel_fbc.c
@@ -100,6 +100,7 @@ static int intel_fbc_calculate_cfb_size(struct intel_crtc *crtc,
 	if (INTEL_INFO(dev_priv)->gen >= 7)
 		lines = min(lines, 2048);
 
+	/* Hardware needs the full buffer stride, not just the active area. */
 	return lines * fb->pitches[0];
 }
 
-- 
2.6.1