From patchwork Sun Jul 7 08:28:46 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 811277 Received: from mail.zeus03.de (zeus03.de [194.117.254.33]) (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 692A2182B9 for ; Sun, 7 Jul 2024 08:28:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=194.117.254.33 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720340944; cv=none; b=El/h4vBZXtbFIIkcEcbVW8L0m48+XroIYBu5P9d0sDoDB/mHsInJJq3+eybDUQ2Tf7+qxeiGLNjepp4Wog8dNyv75ax+qtstrPytq0//U7MF6ZSF8s8cUZ7tqz97XgYPZ5JhJ8+yhJ/zAXy9rZezNUrg5nhgYhuQpu7klCfAuEI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720340944; c=relaxed/simple; bh=OzHvO6rVAWLMwGOBglvI6ki+1drfBQjh5lYtrpaYyX0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VN7J0bR8H77xZA9KDwePd0uuqIihotS7yHAigzGPH4I0roMBQXrrtzSYRzMHtpVWkJVtAXD/kqkUbqbQYqYZuCo2gtJcyfnkWDe7ghLseZcuhIv+nH0e0qDXZydiDEqPMr9rVCMeCFvfmHy9eIzNmZwLdm+MWooDYXN2fBt2nw4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sang-engineering.com; spf=pass smtp.mailfrom=sang-engineering.com; dkim=pass (2048-bit key) header.d=sang-engineering.com header.i=@sang-engineering.com header.b=arzLq/Nt; arc=none smtp.client-ip=194.117.254.33 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sang-engineering.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sang-engineering.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sang-engineering.com header.i=@sang-engineering.com header.b="arzLq/Nt" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= sang-engineering.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; s=k1; bh=nc77Nyudax4dUYLrDvKpXrdOETKQVPpzHynxuO9OHTM=; b=arzLq/ Nt8S9/n3TfoP5EIKzzC3wBgZKnGNfmkbosqRFGu58ZslWTP7n9F/iYadhoC4wTK2 v9Ctt+/9uQCoc8+hzooVNyvf31AXpmTlG2R+z+kcJfS72UF47gYm9GqJ96jHteHu pxa0m75AQjd+CwGwIcAAfKBqr6wp4wHFDvEXGDXS2WolV0lDHBlG81tG/KTmPNr5 R78cfkhPXGRPNYlBclBtfM3mILrMdcNVd631MlO94Avk55GuIszRy9ezFeqMsZmH ABht3fXjFuRqrJPswLcFxf1rwl55CnkZQ3J0gSdtBb7FOnrTn01oIXDi/oi1r3J4 2f4iNuDhj7qYTpzw== Received: (qmail 4044189 invoked from network); 7 Jul 2024 10:28:57 +0200 Received: by mail.zeus03.de with ESMTPSA (TLS_AES_256_GCM_SHA384 encrypted, authenticated); 7 Jul 2024 10:28:57 +0200 X-UD-Smtp-Session: l3s3148p1@okB2FqQcRpRQT+F6 From: Wolfram Sang To: linux-renesas-soc@vger.kernel.org Cc: Wolfram Sang , Dirk Behme , Geert Uytterhoeven , Andi Shyti , Kuninori Morimoto , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/3] i2c: rcar: bring hardware to known state when probing Date: Sun, 7 Jul 2024 10:28:46 +0200 Message-ID: <20240707082848.5424-2-wsa+renesas@sang-engineering.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240707082848.5424-1-wsa+renesas@sang-engineering.com> References: <20240707082848.5424-1-wsa+renesas@sang-engineering.com> Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 When probing, the hardware is not brought into a known state. This may be a problem when a hypervisor restarts Linux without resetting the hardware, leaving an old state running. Make sure the hardware gets initialized, especially interrupts should be cleared and disabled. Reported-by: Dirk Behme Reported-by: Geert Uytterhoeven Closes: https://lore.kernel.org/r/20240702045535.2000393-1-dirk.behme@de.bosch.com Fixes: 6ccbe607132b ("i2c: add Renesas R-Car I2C driver") Signed-off-by: Wolfram Sang --- Should go to for-current. Changes since v1: * renamed new function to *_reset_slave() instead of *_init_slave() which is more appropriate * do not mention refactorization in commit message * added Fixes tag drivers/i2c/busses/i2c-rcar.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index 828aa2ea0fe4..ec73463ea9b5 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -257,6 +257,14 @@ static void rcar_i2c_init(struct rcar_i2c_priv *priv) } } +static void rcar_i2c_reset_slave(struct rcar_i2c_priv *priv) +{ + rcar_i2c_write(priv, ICSIER, 0); + rcar_i2c_write(priv, ICSSR, 0); + rcar_i2c_write(priv, ICSCR, SDBS); + rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */ +} + static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv) { int ret; @@ -1033,11 +1041,8 @@ static int rcar_unreg_slave(struct i2c_client *slave) /* ensure no irq is running before clearing ptr */ disable_irq(priv->irq); - rcar_i2c_write(priv, ICSIER, 0); - rcar_i2c_write(priv, ICSSR, 0); + rcar_i2c_reset_slave(priv); enable_irq(priv->irq); - rcar_i2c_write(priv, ICSCR, SDBS); - rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */ priv->slave = NULL; @@ -1152,7 +1157,9 @@ static int rcar_i2c_probe(struct platform_device *pdev) goto out_pm_disable; } - rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */ + /* Bring hardware to known state */ + rcar_i2c_init(priv); + rcar_i2c_reset_slave(priv); if (priv->devtype < I2C_RCAR_GEN3) { irqflags |= IRQF_NO_THREAD;