From patchwork Wed Jul 3 07:12:03 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 809566 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 D78D31DA31E for ; Wed, 3 Jul 2024 07:16:34 +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=1719990999; cv=none; b=kIP96BulTxQTlUTJwHMFMmKlD/KWUSWzMI0Gp5l2HusU4BaxKt8y2+K95vWJWJaH17BHQuGXquALcODpzYFEo/ccEstTZoWDmQ7SxnHlk//KE1d9G0blOBeTB8ts6hwJmO3rxSBX24CcsQNQu+v1n7GbPxOBrHzKWEmgJE6F5Rg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719990999; c=relaxed/simple; bh=KTDcWsE7q4CAGrggP1GbK428gemPHQuwGvTGjC4cR9s=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=qSH9KtZ+SBYv6PXIbCYvH0I8d/tBimL/26OC0BJVv8de7Vimvc5HLOJL+1b/7uV7gncecLGF7xiLuI8lbU5ZM4R+1ceX3ORek2C1w+EO/yuCzykG21nkRx/ksVB3AB3KDJliRRsiYMs+B1u/ycNW/mDZUNtjZ7MQ69L1qP02Nlc= 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=gDY8nuV8; 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="gDY8nuV8" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= sang-engineering.com; h=from:to:cc:subject:date:message-id :mime-version:content-transfer-encoding; s=k1; bh=3YHgR2kPNRh6LD 6XnaVo+nlQknMU0QRGpA7uAzZVuBs=; b=gDY8nuV8rZhIxJHTHPkdNHFsOmkRiR 6KMji7NU9ODVPWP9ByB4CKCHwTA4wTY+SkuhsFG459pr6Pbne0C4Lu3EeMysjkqy cSKnAi6WtcC7L5v5mMd2l/0v9W7REa63RO9z/4wNBrVedG6gq98mBuOtjd9L64Tj cgHHqTUqoQVRS6bQwMXOKBewGiQdUKlmxC++QwPh/d5ISDXyhc95ZSCUPULAjiqX 2zHkFD9HN3Aa8+PvSKa5mVJZIs2VaNrbH5TDCeYF/30S/GVg7bOemSAIjjZZO0TO ShPxqS8hW0N4hSfnhbbIeTURDIG0C5q+it1oQG1GTB+Qw3aRjoUpJS6A== Received: (qmail 2715603 invoked from network); 3 Jul 2024 09:16:32 +0200 Received: by mail.zeus03.de with ESMTPSA (TLS_AES_256_GCM_SHA384 encrypted, authenticated); 3 Jul 2024 09:16:32 +0200 X-UD-Smtp-Session: l3s3148p1@Zq8ZnFIcBK9ehhrb From: Wolfram Sang To: linux-renesas-soc@vger.kernel.org Cc: Wolfram Sang , Dirk Behme , Geert Uytterhoeven , Andi Shyti , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH] i2c: rcar: bring hardware to known state when probing Date: Wed, 3 Jul 2024 09:12:03 +0200 Message-ID: <20240703071625.5389-1-wsa+renesas@sang-engineering.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Probably due to a lot of refactorization, the hardware was not brought into a known state in probe. 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 Signed-off-by: Wolfram Sang --- Here is my proposal to fix the issue reported by Dirk. Build tested. I can do proper testing on HW only tomorrow. But so you know already... It is strange to add another "_slave" function to the driver while I work on removing such language from I2C somewhere else. "Consistency" is the answer here. The driver will be converted as well. But then as a whole. 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..00a885205075 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_init_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_init_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_init_slave(priv); if (priv->devtype < I2C_RCAR_GEN3) { irqflags |= IRQF_NO_THREAD;