linux-kernel - [PATCH] drm/stm: ltdc: reset controller to avoid partial refresh

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-next>] [day] [month] [year] [list]

Date:   Wed, 3 Apr 2019 11:24:13 +0200
From:   Yannick Fertré <yannick.fertre@...com>
To:     Yannick Fertre <yannick.fertre@...com>,
        Philippe Cornu <philippe.cornu@...com>,
        Benjamin Gaignard <benjamin.gaignard@...com>,
        Vincent Abriou <vincent.abriou@...com>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        Maxime Coquelin <mcoquelin.stm32@...il.com>,
        Alexandre Torgue <alexandre.torgue@...com>,
        <dri-devel@...ts.freedesktop.org>,
        <linux-stm32@...md-mailman.stormreply.com>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>
Subject: [PATCH] drm/stm: ltdc: reset controller to avoid partial refresh

Display controller reset must be done as soon as possible after enable
the clock to avoid partial refresh on screen.

Signed-off-by: Yannick Fertré <yannick.fertre@...com>
---
 drivers/gpu/drm/stm/ltdc.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index 32fd6a3..7bbe61c 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -1134,6 +1134,12 @@ int ltdc_load(struct drm_device *ddev)
 		return -ENODEV;
 	}
 
+	if (!IS_ERR(rstc)) {
+		reset_control_assert(rstc);
+		usleep_range(10, 20);
+		reset_control_deassert(rstc);
+	}
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	ldev->regs = devm_ioremap_resource(dev, res);
 	if (IS_ERR(ldev->regs)) {
@@ -1156,12 +1162,6 @@ int ltdc_load(struct drm_device *ddev)
 		}
 	}
 
-	if (!IS_ERR(rstc)) {
-		reset_control_assert(rstc);
-		usleep_range(10, 20);
-		reset_control_deassert(rstc);
-	}
-
 	/* Disable interrupts */
 	reg_clear(ldev->regs, LTDC_IER,
 		  IER_LIE | IER_RRIE | IER_FUIE | IER_TERRIE);
-- 
2.7.4