From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 03261C98318 for ; Thu, 24 Sep 2026 18:42:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:To:From:Date:Reply-To:Cc: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=2QsMlawU20NpzMEJzjiEnzG65JE1GUevO/QYWxzAmEw=; b=bj7B/vmgaUqNISHhdBXQ2PIJEX MD2yqhVvLHApj3XQmubNhFVIVYMSU1bXUzeKlaqfcLzOoT8zEyTlj7WkMYLisFoYhqZAbeeLVKs83 ajBvRP7XEpWOZHUihk26wGqhS0kZWAcZIAEacwDZixr4UKJCCQt6j4ZmOFt3MVJyWWeb6pE/1Pb9a QB0cJDIWEYG1HKE1WFsf8tg2kxdtrxVvJMZrO+sl16cF48TnU33fSeW8SGLTApjd4OuOSArY6tL3i vhk4Waw6Ah7oNhenSSNZ3MQ8rN6V6qVUdSit9xtYeBkuQdEcz2yIMkLmbqweSedGsj7SqQdL+v8UJ a/vomD7Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x9oOq-0000000BwmF-0Fga; Thu, 24 Sep 2026 18:42:28 +0000 Received: from pidgin.makrotopia.org ([2a07:2ec0:3002::65]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x9oOj-0000000BwiT-3FR9; Thu, 24 Sep 2026 18:42:23 +0000 Received: from local by pidgin.makrotopia.org with esmtpsa (TLS1.3:TLS_AES_256_GCM_SHA384:256:X25519MLKEM768) (Exim 4.100) (envelope-from ) id 1x9oOf-000000007Qp-00dt; Thu, 24 Sep 2026 18:42:17 +0000 Date: Thu, 24 Sep 2026 19:42:13 +0100 From: Daniel Golle To: Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Luca Ceresoli , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Matthias Brugger , AngeloGioacchino Del Regno , Allen Chen , Hermes Wu , Pin-yen Lin , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Subject: [PATCH v7 12/14] drm/bridge: it6505: don't write an error code back to the reset register Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260924_114221_850413_08D8C353 X-CRM114-Status: GOOD ( 12.94 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org it6505_audio_input() saves REG_RESET_CTRL, pulses AUDIO_RESET and writes the saved value back. it6505_read() returns a negative errno on i2c failure, which regmap truncates to eight bits on the way out: -EIO turns into 0xfb, holding video, audio, AUX and HDCP in reset. A failed REG_AUDIO_INPUT_FREQ read is just as wrong, as any negative value passes the != 0xFF test and reports an audio clock that was never sampled. Bail out before touching the register and only report audio input for a usable readback. Fixes: b5c84a9edcd4 ("drm/bridge: add it6505 driver") Signed-off-by: Daniel Golle --- v7: no changes v6: new patch --- drivers/gpu/drm/bridge/ite-it6505.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c index d6ba28d1c963..36bb4e905ef8 100644 --- a/drivers/gpu/drm/bridge/ite-it6505.c +++ b/drivers/gpu/drm/bridge/ite-it6505.c @@ -1516,12 +1516,15 @@ static bool it6505_audio_input(struct it6505 *it6505) int reg05, regbe; reg05 = it6505_read(it6505, REG_RESET_CTRL); + if (reg05 < 0) + return false; + it6505_set_bits(it6505, REG_RESET_CTRL, AUDIO_RESET, 0x00); usleep_range(3000, 4000); regbe = it6505_read(it6505, REG_AUDIO_INPUT_FREQ); it6505_write(it6505, REG_RESET_CTRL, reg05); - return regbe != 0xFF; + return regbe > 0 && regbe != 0xFF; } static void it6505_setup_audio_channel_status(struct it6505 *it6505) -- 2.55.0