linux-kernel - [PATCH v1 7/9] drm/bridge: tc358768: fix TXTAGOCNT computation

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: <20230427142934.55435-8-francesco@dolcini.it>
Date:   Thu, 27 Apr 2023 16:29:32 +0200
From:   Francesco Dolcini <francesco@...cini.it>
To:     Andrzej Hajda <andrzej.hajda@...el.com>,
        Neil Armstrong <neil.armstrong@...aro.org>,
        Robert Foss <rfoss@...nel.org>,
        Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
        Jonas Karlman <jonas@...boo.se>,
        Jernej Skrabec <jernej.skrabec@...il.com>,
        tomi.valkeinen@...asonboard.com, dri-devel@...ts.freedesktop.org
Cc:     Francesco Dolcini <francesco.dolcini@...adex.com>,
        David Airlie <airlied@...il.com>,
        Daniel Vetter <daniel@...ll.ch>, linux-kernel@...r.kernel.org
Subject: [PATCH v1 7/9] drm/bridge: tc358768: fix TXTAGOCNT computation

From: Francesco Dolcini <francesco.dolcini@...adex.com>

Correct computation of TXTAGOCNT register.

This register must be set to a value that ensure that the
TTA-GO period = (4 x TLPX)

with the actual value of TTA-GO being

4 x (TXTAGOCNT + 1) x (HSByteClk cycle)

Fixes: ff1ca6397b1d ("drm/bridge: Add tc358768 driver")
Signed-off-by: Francesco Dolcini <francesco.dolcini@...adex.com>
---
 drivers/gpu/drm/bridge/tc358768.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/tc358768.c b/drivers/gpu/drm/bridge/tc358768.c
index 36e33cba59a2..854fc04f08d0 100644
--- a/drivers/gpu/drm/bridge/tc358768.c
+++ b/drivers/gpu/drm/bridge/tc358768.c
@@ -795,7 +795,7 @@ static void tc358768_bridge_pre_enable(struct drm_bridge *bridge)
 
 	/* TXTAGOCNT[26:16] RXTASURECNT[10:0] */
 	val = tc358768_to_ns((lptxcnt + 1) * dsibclk_nsk * 4);
-	val = tc358768_ns_to_cnt(val, dsibclk_nsk) - 1;
+	val = tc358768_ns_to_cnt(val, dsibclk_nsk) / 4 - 1;
 	val2 = tc358768_ns_to_cnt(tc358768_to_ns((lptxcnt + 1) * dsibclk_nsk),
 				  dsibclk_nsk) - 2;
 	val = val << 16 | val2;
-- 
2.25.1