linux-kernel - [PATCH v4 12/14] drm/mxsfb: Clear OUTSTANDING

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]

Message-Id: <1567078215-31601-13-git-send-email-robert.chiras@nxp.com>
Date:   Thu, 29 Aug 2019 14:30:13 +0300
From:   Robert Chiras <robert.chiras@....com>
To:     Guido Günther <agx@...xcpu.org>,
        Marek Vasut <marex@...x.de>, Stefan Agner <stefan@...er.ch>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Shawn Guo <shawnguo@...nel.org>,
        Sascha Hauer <s.hauer@...gutronix.de>,
        Fabio Estevam <festevam@...il.com>
Cc:     Pengutronix Kernel Team <kernel@...gutronix.de>,
        NXP Linux Team <linux-imx@....com>,
        dri-devel@...ts.freedesktop.org, devicetree@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH v4 12/14] drm/mxsfb: Clear OUTSTANDING_REQS bits

Bit 21 can alter the CTRL2_OUTSTANDING_REQS value right after the eLCDIF
is enabled, since it comes up with default value of 1 (this behaviour
has been seen on some imx8 platforms).
In order to fix this, clear CTRL2_OUTSTANDING_REQS bits before setting
its value.

Signed-off-by: Robert Chiras <robert.chiras@....com>
Tested-by: Guido Günther <agx@...xcpu.org>
---
 drivers/gpu/drm/mxsfb/mxsfb_crtc.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
index e727f5e..a12f53d 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
@@ -225,6 +225,13 @@ static void mxsfb_enable_controller(struct mxsfb_drm_private *mxsfb)
 	clk_prepare_enable(mxsfb->clk);
 
 	if (mxsfb->devdata->ipversion >= 4) {
+		/*
+		 * On some platforms, bit 21 is defaulted to 1, which may alter
+		 * the below setting. So, to make sure we have the right setting
+		 * clear all the bits for CTRL2_OUTSTANDING_REQS.
+		 */
+		writel(CTRL2_OUTSTANDING_REQS(0x7),
+		       mxsfb->base + LCDC_V4_CTRL2 + REG_CLR);
 		writel(CTRL2_OUTSTANDING_REQS(REQ_16),
 		       mxsfb->base + LCDC_V4_CTRL2 + REG_SET);
 		/* Assert LCD Reset bit */
-- 
2.7.4