linux-kernel - [PATCH 2/3] drm/sun4i: sun8i_csc: Simplify register writes

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Sat, 13 Jul 2019 14:03:45 +0200
From:   Jernej Skrabec <jernej.skrabec@...l.net>
To:     maxime.ripard@...tlin.com, wens@...e.org
Cc:     airlied@...ux.ie, daniel@...ll.ch, dri-devel@...ts.freedesktop.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        linux-sunxi@...glegroups.com
Subject: [PATCH 2/3] drm/sun4i: sun8i_csc: Simplify register writes

It turns out addition of 0x200 to constant parts (+0.5) is not really
necessary. Besides, we can consider that before and fix value in CSC
matrix.

This simplifies register writes quiet a bit.

Signed-off-by: Jernej Skrabec <jernej.skrabec@...l.net>
---
 drivers/gpu/drm/sun4i/sun8i_csc.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun8i_csc.c b/drivers/gpu/drm/sun4i/sun8i_csc.c
index b8c059f1a118..e07b7876d89b 100644
--- a/drivers/gpu/drm/sun4i/sun8i_csc.c
+++ b/drivers/gpu/drm/sun4i/sun8i_csc.c
@@ -69,7 +69,7 @@ static void sun8i_csc_set_coefficients(struct regmap *map, u32 base,
 				       enum sun8i_csc_mode mode)
 {
 	const u32 *table;
-	int i, data;
+	u32 base_reg;
 
 	switch (mode) {
 	case SUN8I_CSC_MODE_YUV2RGB:
@@ -83,13 +83,8 @@ static void sun8i_csc_set_coefficients(struct regmap *map, u32 base,
 		return;
 	}
 
-	for (i = 0; i < 12; i++) {
-		data = table[i];
-		/* For some reason, 0x200 must be added to constant parts */
-		if (((i + 1) & 3) == 0)
-			data += 0x200;
-		regmap_write(map, SUN8I_CSC_COEFF(base, i), data);
-	}
+	base_reg = SUN8I_CSC_COEFF(base, 0);
+	regmap_bulk_write(map, base_reg, table, 12);
 }
 
 static void sun8i_de3_ccsc_set_coefficients(struct regmap *map, int layer,
-- 
2.22.0