From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 333A82F24 for ; Wed, 12 Apr 2023 08:37:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AEEF9C433EF; Wed, 12 Apr 2023 08:37:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681288656; bh=NhsScW4y2Y9pkswRHZwszDvBFBlk2v4xUQOht6nyfu0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nlYRzS35WvAYYkcELGY3+Mv9WbvtrTqna4XKFA0QX+juZ6CbH1FKAhq/NlJ8lHg6U oCnc07gd20rQYiOYkcZCKnaEFoMuunwW85eX9UuD1rqBVE/0xQMeVlbcnZ/7Xk7rHJ OPMRO8PcfVbpFRvkGNnRZchz8Es0hyspaGgjteX0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, William Breathitt Gray , Jonathan Cameron Subject: [PATCH 5.15 61/93] iio: dac: cio-dac: Fix max DAC write value check for 12-bit Date: Wed, 12 Apr 2023 10:34:02 +0200 Message-Id: <20230412082825.709517725@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230412082823.045155996@linuxfoundation.org> References: <20230412082823.045155996@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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;