linux-kernel - [PATCH] drm/vboxvideo: Avoid double check buffer_overflow in vbva

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Date:   Sat,  6 Apr 2019 08:18:50 +0000
From:   Sidong Yang <realwakka@...il.com>
To:     Hans de Goede <hdegoede@...hat.com>
Cc:     Sidong Yang <realwakka@...il.com>, David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: [PATCH] drm/vboxvideo: Avoid double check buffer_overflow in vbva_write()

In vbva_write(), We do not need to double check available chunk size if
chunk is smaller than available buffer. Put the second if clause in the
first if clause and avoid check twice.

Signed-off-by: Sidong Yang <realwakka@...il.com>
---
 drivers/gpu/drm/vboxvideo/vbva_base.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/vboxvideo/vbva_base.c b/drivers/gpu/drm/vboxvideo/vbva_base.c
index 36bc9824ec3f..a0c185acf37a 100644
--- a/drivers/gpu/drm/vboxvideo/vbva_base.c
+++ b/drivers/gpu/drm/vboxvideo/vbva_base.c
@@ -80,14 +80,14 @@ bool vbva_write(struct vbva_buf_ctx *vbva_ctx, struct gen_pool *ctx,
 		if (chunk >= available) {
 			vbva_buffer_flush(ctx);
 			available = vbva_buffer_available(vbva);
-		}
-
-		if (chunk >= available) {
-			if (WARN_ON(available <= vbva->partial_write_tresh)) {
-				vbva_ctx->buffer_overflow = true;
-				return false;
+			if (chunk >= available) {
+				if (WARN_ON(available <= vbva->partial_write_tresh)) {
+					vbva_ctx->buffer_overflow = true;
+					return false;
+				}
+				chunk = available - vbva->partial_write_tresh;
 			}
-			chunk = available - vbva->partial_write_tresh;
+
 		}
 
 		vbva_buffer_place_data_at(vbva_ctx, p, chunk,
-- 
2.11.0