From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=4dx/=CN=vger.kernel.org=linux-spi-owner@kernel.org>
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=-13.1 required=3.0 tests=BAYES_00,DKIM_SIGNED,
	DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,
	MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,
	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 EC502C43461
	for <linux-spi@archiver.kernel.org>; Fri,  4 Sep 2020 00:28:20 +0000 (UTC)
Received: from vger.kernel.org (vger.kernel.org [23.128.96.18])
	by mail.kernel.org (Postfix) with ESMTP id B58F420758
	for <linux-spi@archiver.kernel.org>; Fri,  4 Sep 2020 00:28:20 +0000 (UTC)
Authentication-Results: mail.kernel.org;
	dkim=pass (2048-bit key) header.d=alliedtelesis.co.nz header.i=@alliedtelesis.co.nz header.b="a6JRNAd7"
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1728037AbgIDA2U (ORCPT <rfc822;linux-spi@archiver.kernel.org>);
        Thu, 3 Sep 2020 20:28:20 -0400
Received: from gate2.alliedtelesis.co.nz ([202.36.163.20]:42472 "EHLO
        gate2.alliedtelesis.co.nz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1726397AbgIDA2T (ORCPT
        <rfc822;linux-spi@vger.kernel.org>); Thu, 3 Sep 2020 20:28:19 -0400
Received: from mmarshal3.atlnz.lc (mmarshal3.atlnz.lc [10.32.18.43])
        (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
        (Client did not present a certificate)
        by gate2.alliedtelesis.co.nz (Postfix) with ESMTPS id 677E8806B5;
        Fri,  4 Sep 2020 12:28:16 +1200 (NZST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alliedtelesis.co.nz;
        s=mail181024; t=1599179296;
        bh=PeKvL5ah8tfQA9K2g0Ur26fGWX24dwpS7/gFm9K63hM=;
        h=From:To:Cc:Subject:Date;
        b=a6JRNAd7aob5eI2XZzkOFb5ZZ02HGxer81YI0ujs2yAULCbfguWR7cQ+CrLJSrC+J
         VaVPBSsq46CnCoonOoIOCxz0vxfLGsIV49E5dVeBrVX9szyJ+6/dwUhc6FaBaCDlkE
         BeEANfSYURAT+Q+XP1BcK8aFzg0WbS50GX26IpVG8U0/u90OPDKBQ8p5rR0PtaFS3z
         z+yYp7LizkapHRnsXR3zqNx5YcRYE0qkqhlpD83pi9bs0w3rsu93n9aQ9d9nxPs7Lb
         SRjslvAP5I0BA/5Vrj0P0YBgOMPbTO9YvOxnoSxeiTC43ROu9pKIqsw16zMU9KWRXe
         a7h3Pf3onz31w==
Received: from smtp (Not Verified[10.32.16.33]) by mmarshal3.atlnz.lc with Trustwave SEG (v7,5,8,10121)
        id <B5f518a1e0000>; Fri, 04 Sep 2020 12:28:14 +1200
Received: from chrisp-dl.ws.atlnz.lc (chrisp-dl.ws.atlnz.lc [10.33.22.20])
        by smtp (Postfix) with ESMTP id EB27A13EEBA;
        Fri,  4 Sep 2020 12:28:15 +1200 (NZST)
Received: by chrisp-dl.ws.atlnz.lc (Postfix, from userid 1030)
        id 2ABBB280060; Fri,  4 Sep 2020 12:28:16 +1200 (NZST)
From:   Chris Packham <chris.packham@alliedtelesis.co.nz>
To:     broonie@kernel.org, npiggin@gmail.com, hkallweit1@gmail.com
Cc:     linux-spi@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        linux-kernel@vger.kernel.org,
        Chris Packham <chris.packham@alliedtelesis.co.nz>,
        stable@vger.kernel.org
Subject: [PATCH] spi: fsl-espi: Only process interrupts for expected events
Date:   Fri,  4 Sep 2020 12:28:12 +1200
Message-Id: <20200904002812.7300-1-chris.packham@alliedtelesis.co.nz>
X-Mailer: git-send-email 2.28.0
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
x-atlnz-ls: pat
Sender: linux-spi-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-spi.vger.kernel.org>
X-Mailing-List: linux-spi@vger.kernel.org

The SPIE register contains counts for the TX FIFO so any time the irq
handler was invoked we would attempt to process the RX/TX fifos. Use the
SPIM value to mask the events so that we only process interrupts that
were expected.

This was a latent issue exposed by commit 3282a3da25bd ("powerpc/64:
Implement soft interrupt replay in C").

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Cc: stable@vger.kernel.org
---

Notes:
    I've tested this on a T2080RDB and a custom board using the T2081 SoC=
. With
    this change I don't see any spurious instances of the "Transfer done =
but
    SPIE_DON isn't set!" or "Transfer done but rx/tx fifo's aren't empty!=
" messages
    and the updates to spi flash are successful.
   =20
    I think this should go into the stable trees that contain 3282a3da25b=
d but I
    haven't added a Fixes: tag because I think 3282a3da25bd exposed the i=
ssue as
    opposed to causing it.

 drivers/spi/spi-fsl-espi.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c
index 7e7c92cafdbb..cb120b68c0e2 100644
--- a/drivers/spi/spi-fsl-espi.c
+++ b/drivers/spi/spi-fsl-espi.c
@@ -574,13 +574,14 @@ static void fsl_espi_cpu_irq(struct fsl_espi *espi,=
 u32 events)
 static irqreturn_t fsl_espi_irq(s32 irq, void *context_data)
 {
 	struct fsl_espi *espi =3D context_data;
-	u32 events;
+	u32 events, mask;
=20
 	spin_lock(&espi->lock);
=20
 	/* Get interrupt events(tx/rx) */
 	events =3D fsl_espi_read_reg(espi, ESPI_SPIE);
-	if (!events) {
+	mask =3D fsl_espi_read_reg(espi, ESPI_SPIM);
+	if (!(events & mask)) {
 		spin_unlock(&espi->lock);
 		return IRQ_NONE;
 	}
--=20
2.28.0