From patchwork Mon Jun 27 17:06:42 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Walle X-Patchwork-Id: 12896917 X-Patchwork-Delegate: kuba@kernel.org 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 34290C433EF for ; Mon, 27 Jun 2022 17:06:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239786AbiF0RGy (ORCPT ); Mon, 27 Jun 2022 13:06:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239773AbiF0RGx (ORCPT ); Mon, 27 Jun 2022 13:06:53 -0400 Received: from ssl.serverraum.org (ssl.serverraum.org [176.9.125.105]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 091D918E07; Mon, 27 Jun 2022 10:06:50 -0700 (PDT) Received: from mwalle01.kontron.local. (unknown [213.135.10.150]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ssl.serverraum.org (Postfix) with ESMTPSA id EC7C222247; Mon, 27 Jun 2022 19:06:48 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1656349609; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=hdSEEfSPwayxYsX2lkz6wJR/gBxqwicuOttb5J8K25U=; b=Z+N8P1RsBooq7XLfGMvP2smcldc93s2snh+nCmRRggHy9acquHGhKNK6oixXH+yM8ZMxqs rJsCWtTz1A/gsD5QjwA09PFCj88dRaIisjNHHI1AxirJHBjmzV3vnfh1aNqMB1CzYrgCNl kMd3mNi/O46V6T4P5kx0vOpJDmZLWmA= From: Michael Walle To: Krzysztof Kozlowski Cc: =?utf-8?q?Cl=C3=A9ment_Perrochaud?= , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Michael Walle Subject: [PATCH v2 1/2] NFC: nxp-nci: Don't issue a zero length i2c_master_read() Date: Mon, 27 Jun 2022 19:06:42 +0200 Message-Id: <20220627170643.98239-1-michael@walle.cc> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org 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 --- changes since v1: - none drivers/nfc/nxp-nci/i2c.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/nfc/nxp-nci/i2c.c b/drivers/nfc/nxp-nci/i2c.c index 7e451c10985d..e8f3b35afbee 100644 --- 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 nxp_nci_i2c_phy *phy, 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,