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 4AA51C6FD18 for ; Tue, 18 Apr 2023 12:29:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231556AbjDRM3S (ORCPT ); Tue, 18 Apr 2023 08:29:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39728 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231575AbjDRM3L (ORCPT ); Tue, 18 Apr 2023 08:29:11 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E27967EE3 for ; Tue, 18 Apr 2023 05:28:49 -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 BDA77631C3 for ; Tue, 18 Apr 2023 12:28:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF74BC433EF; Tue, 18 Apr 2023 12:28:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681820929; bh=NhsScW4y2Y9pkswRHZwszDvBFBlk2v4xUQOht6nyfu0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uf1uavm5JPZRXo3pZ82SveK/N1h16tPh5Q5oVB9DdmhqsFRuTDSuQRC+tN1WdViif 7HE+km4t9m2M4HQSq0deCHhheOJi19R5SLivmheKwiPfbDJtDYbFNZ8cLYollocOVO 5UOkC00ykqdmITR26yaKcEPWrFOqZpaFt7K/ekCg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, William Breathitt Gray , Jonathan Cameron Subject: [PATCH 5.4 26/92] iio: dac: cio-dac: Fix max DAC write value check for 12-bit Date: Tue, 18 Apr 2023 14:21:01 +0200 Message-Id: <20230418120305.747051895@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230418120304.658273364@linuxfoundation.org> References: <20230418120304.658273364@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 @@ -66,8 +66,8 @@ 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;