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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A97BDC77B78 for ; Tue, 18 Apr 2023 12:25:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231441AbjDRMZv (ORCPT ); Tue, 18 Apr 2023 08:25:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34184 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231387AbjDRMZl (ORCPT ); Tue, 18 Apr 2023 08:25:41 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3EE2FAD33 for ; Tue, 18 Apr 2023 05:25:10 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1127F6313A for ; Tue, 18 Apr 2023 12:25:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 23042C433EF; Tue, 18 Apr 2023 12:25:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681820709; bh=RCcIzMqCRkDHlbXcY9Qu9etEFyg9ePZW9O64p7a5/C4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=epJ2L2X7qMAWDAXVyO5GX75+u/rKECxZyYziB7Gcy6OEIjPPUYR0zZEQffsThi1zI 16XahZMgyhUTuVTaDsCP2BxLd6Qln8fsH7RvOU/sLmatuXzlV3NG4GyzbzNmBNwswe 5SjQVfjE9TMsSIDyOoDVcERpmc6cHvp4jUcUCSsY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, William Breathitt Gray , Jonathan Cameron Subject: [PATCH 4.14 09/37] iio: dac: cio-dac: Fix max DAC write value check for 12-bit Date: Tue, 18 Apr 2023 14:21:19 +0200 Message-Id: <20230418120255.002127672@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230418120254.687480980@linuxfoundation.org> References: <20230418120254.687480980@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: William Breathitt Gray commit c3701185ee1973845db088d8b0fc443397ab0eb2 upstream. The CIO-DAC series of devices only supports DAC values up to 12-bit rather than 16-bit. Trying to write a 16-bit value results in only the lower 12 bits affecting the DAC output which is not what the user expects. Instead, adjust the DAC write value check to reject values larger than 12-bit so that they fail explicitly as invalid for the user. Fixes: 3b8df5fd526e ("iio: Add IIO support for the Measurement Computing CIO-DAC family") Cc: stable@vger.kernel.org Signed-off-by: William Breathitt Gray Link: https://lore.kernel.org/r/20230311002248.8548-1-william.gray@linaro.org Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/dac/cio-dac.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/iio/dac/cio-dac.c +++ b/drivers/iio/dac/cio-dac.c @@ -74,8 +74,8 @@ static int cio_dac_write_raw(struct iio_ if (mask != IIO_CHAN_INFO_RAW) return -EINVAL; - /* DAC can only accept up to a 16-bit value */ - if ((unsigned int)val > 65535) + /* DAC can only accept up to a 12-bit value */ + if ((unsigned int)val > 4095) return -EINVAL; priv->chan_out_states[chan->channel] = val;