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 X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A425BC3F2D2 for ; Tue, 3 Mar 2020 02:49:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 738D824699 for ; Tue, 3 Mar 2020 02:49:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583203771; bh=/OvgG2nfz29KAV+9BKomIZu5mQCBT/tB8LByXnZ0JvU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=nnXS4PSgBrI15fqB+5nRJ6MaJa/0DvM+yLVSHobTzq/X38pELryj2KRh7C/orkGhZ vIirgKa3+2Lo0jXXR/NVI3+pT6R5hWW/jmzy+yRoqm0pbpRxXpN58RsDVi4iG1GhDX +jyOD6D+H/2p9SJe/tYl4l3DmRJ+0+4lUD7iEEG8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728897AbgCCCta (ORCPT ); Mon, 2 Mar 2020 21:49:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:45680 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728300AbgCCCt2 (ORCPT ); Mon, 2 Mar 2020 21:49:28 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 94B43246D9; Tue, 3 Mar 2020 02:49:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583203767; bh=/OvgG2nfz29KAV+9BKomIZu5mQCBT/tB8LByXnZ0JvU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d6cbtSnijGSl1qvz0Jq5wxIlq6SaNyByiEAMcjYi3ZOyA1qVgm8roPHfnVfX3cu0e uNqh5bAh2astwe8/HwTJhlWDxwY82R562yTr3LtLh0l6FKe3HrAUrxeHtPQEdNt9DV aEpTNrHEDv7Ioj5GUHlX+WGDkq4fSYw9xu7VfeUo= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dmitry Osipenko , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 28/32] nfc: pn544: Fix occasional HW initialization failure Date: Mon, 2 Mar 2020 21:48:47 -0500 Message-Id: <20200303024851.10054-28-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200303024851.10054-1-sashal@kernel.org> References: <20200303024851.10054-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dmitry Osipenko [ Upstream commit c3331d2fe3fd4d5e321f2467d01f72de7edfb5d0 ] The PN544 driver checks the "enable" polarity during of driver's probe and it's doing that by turning ON and OFF NFC with different polarities until enabling succeeds. It takes some time for the hardware to power-down, and thus, to deassert the IRQ that is raised by turning ON the hardware. Since the delay after last power-down of the polarity-checking process is missed in the code, the interrupt may trigger immediately after installing the IRQ handler (right after the checking is done), which results in IRQ handler trying to touch the disabled HW and ends with marking NFC as 'DEAD' during of the driver's probe: pn544_hci_i2c 1-002a: NFC: nfc_en polarity : active high pn544_hci_i2c 1-002a: NFC: invalid len byte shdlc: llc_shdlc_recv_frame: NULL Frame -> link is dead This patch fixes the occasional NFC initialization failure on Nexus 7 device. Signed-off-by: Dmitry Osipenko Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/nfc/pn544/i2c.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/nfc/pn544/i2c.c b/drivers/nfc/pn544/i2c.c index d0207f8e68b7c..dcef73eb41206 100644 --- a/drivers/nfc/pn544/i2c.c +++ b/drivers/nfc/pn544/i2c.c @@ -236,6 +236,7 @@ static void pn544_hci_i2c_platform_init(struct pn544_i2c_phy *phy) out: gpiod_set_value_cansleep(phy->gpiod_en, !phy->en_polarity); + usleep_range(10000, 15000); } static void pn544_hci_i2c_enable_mode(struct pn544_i2c_phy *phy, int run_mode) -- 2.20.1