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 7FF9DCCA491 for ; Tue, 5 Jul 2022 12:19:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236936AbiGEMSX (ORCPT ); Tue, 5 Jul 2022 08:18:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54102 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232197AbiGEMJX (ORCPT ); Tue, 5 Jul 2022 08:09:23 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75091186E8; Tue, 5 Jul 2022 05:09:21 -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 1251861968; Tue, 5 Jul 2022 12:09:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 21691C36AE2; Tue, 5 Jul 2022 12:09:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1657022960; bh=jzkFDmSMQEdcCXzeN1VJevw4S6A6EmA4JQDB+UhsubQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kDZYnXzFOio32WHkCLTRbToJ65Afe89Ir5mfxwPNurvJ5xJv2Ts39fV01nakQSAh1 eNvi44VDlpgNYvJfIw8Qcz+x+2B49rW5qGsDGMSADM6a5H5k6ErmNpWS0kHNQcQRKM G+1qiGkOKZQF1kcciyUqYgghyHEwFgKSZChwEMsY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Walle , Krzysztof Kozlowski , "David S. Miller" Subject: [PATCH 5.10 35/84] NFC: nxp-nci: Dont issue a zero length i2c_master_read() Date: Tue, 5 Jul 2022 13:57:58 +0200 Message-Id: <20220705115616.348329371@linuxfoundation.org> X-Mailer: git-send-email 2.37.0 In-Reply-To: <20220705115615.323395630@linuxfoundation.org> References: <20220705115615.323395630@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Michael Walle commit eddd95b9423946aaacb55cac6a9b2cea8ab944fc upstream. There are packets which doesn't have a payload. In that case, the second i2c_master_read() will have a zero length. But because the NFC controller doesn't have any data left, it will NACK the I2C read and -ENXIO will be returned. In case there is no payload, just skip the second i2c master read. Fixes: 6be88670fc59 ("NFC: nxp-nci_i2c: Add I2C support to NXP NCI driver") Signed-off-by: Michael Walle Reviewed-by: Krzysztof Kozlowski Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/nfc/nxp-nci/i2c.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/nfc/nxp-nci/i2c.c +++ b/drivers/nfc/nxp-nci/i2c.c @@ -162,6 +162,9 @@ static int nxp_nci_i2c_nci_read(struct n skb_put_data(*skb, (void *)&header, NCI_CTRL_HDR_SIZE); + if (!header.plen) + return 0; + r = i2c_master_recv(client, skb_put(*skb, header.plen), header.plen); if (r != header.plen) { nfc_err(&client->dev,