linux-kernel - [PATCH] drm: atmel-hlcdc: reset layer A2Q and UPDATE bits when disabling it

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>] [day] [month] [year] [list]

Message-Id: <1423236789-6859-1-git-send-email-boris.brezillon@free-electrons.com>
Date:	Fri,  6 Feb 2015 16:33:09 +0100
From:	Boris Brezillon <boris.brezillon@...e-electrons.com>
To:	David Airlie <airlied@...ux.ie>, dri-devel@...ts.freedesktop.org,
	Nicolas Ferre <nicolas.ferre@...el.com>,
	Jean-Christophe Plagniol-Villard <plagnioj@...osoft.com>,
	Alexandre Belloni <alexandre.belloni@...e-electrons.com>
Cc:	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	Boris Brezillon <boris.brezillon@...e-electrons.com>
Subject: [PATCH] drm: atmel-hlcdc: reset layer A2Q and UPDATE bits when disabling it

The A2Q (Add To Queue) and UPDATE bits are left in their previous state
when resetting the layer.
This lead to weird behavior when enabling the plane again: the framebuffer
previously queued is dequeued and we end up with access to an old memory
region.

Reset those bits when resetting the channel.

Signed-off-by: Boris Brezillon <boris.brezillon@...e-electrons.com>
---
 drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_layer.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_layer.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_layer.c
index 063d2a7..e79bd9b 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_layer.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_layer.c
@@ -311,7 +311,8 @@ int atmel_hlcdc_layer_disable(struct atmel_hlcdc_layer *layer)
 
 	/* Disable the layer */
 	regmap_write(regmap, desc->regs_offset + ATMEL_HLCDC_LAYER_CHDR,
-		     ATMEL_HLCDC_LAYER_RST);
+		     ATMEL_HLCDC_LAYER_RST | ATMEL_HLCDC_LAYER_A2Q |
+		     ATMEL_HLCDC_LAYER_UPDATE);
 
 	/* Clear all pending interrupts */
 	regmap_read(regmap, desc->regs_offset + ATMEL_HLCDC_LAYER_ISR, &isr);
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/