From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pidgin.makrotopia.org (pidgin.makrotopia.org [185.142.180.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C5C2648551B for ; Thu, 24 Sep 2026 18:42:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.142.180.65 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790275347; cv=none; b=soqb+DPmvGJmjoxrb9b3XlMGCEs1BDrkwzvVlUrRvQnm/qR0qPQVV/Z8ThaLbdRCU+76HGsdE0eR+qusrW9V7mJ1xe+3047kVW490s71aHdJ8VeZWA0MYxIGqobmRYrQTdH4zmC5Z5UnGpRfhFTZxklF5hnzPsaKsLCZz4SrBdg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790275347; c=relaxed/simple; bh=bkcQJm28yxkLUOYYiMPederQCP9Q8mBiaVo5oPB5mW4=; h=Date:From:To:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NcXPlBebVmo/VhUg9Y7plNGcibjzvmlRYpq1byykCwCxTw61aceSv7q/+f0p/XzKAGU+Q6QEMkxS1PQHiMhDrs+9ZCLop/tGPfccjfie/KIoBbochOEz28ycUICSxGX79vfbKrQouqYS8tPW7Fsn3uWyGvRzBRoLugbBLVXRnhQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=makrotopia.org; spf=pass smtp.mailfrom=makrotopia.org; arc=none smtp.client-ip=185.142.180.65 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=makrotopia.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=makrotopia.org 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: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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