From patchwork Mon Feb 20 16:16:28 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthias Schiffer X-Patchwork-Id: 655251 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 55E2AC05027 for ; Mon, 20 Feb 2023 16:17:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231346AbjBTQRn (ORCPT ); Mon, 20 Feb 2023 11:17:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33292 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232192AbjBTQRm (ORCPT ); Mon, 20 Feb 2023 11:17:42 -0500 Received: from mx1.tq-group.com (mx1.tq-group.com [93.104.207.81]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DA1D86193; Mon, 20 Feb 2023 08:17:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tq-group.com; i=@tq-group.com; q=dns/txt; s=key1; t=1676909860; x=1708445860; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=m8U/qv7GUyyJtoJ/cmMrOe+OYej/LgVV8kl3LQxG2EQ=; b=QShoYGpULHw6T2K/CIBpTfxAChbEnG9hAijx8wNRHPt6l5YD29bOf6ol VSb8KEEGbw5OUvWDYgqqjuFfZrmky48eJrs/0hJHXWG+3Q4kHUmJGmGSZ ivj7z2yrJY6/Zsno5k7ORo83gKDQHH4DGEFvGprF4lAa+pjlfs7adxNTv S4VdyR1GE62oO1/WOTUPLvKS/pMph8niit3ErlIQ8nkIWhIRMqerqYcvm kkhSoVyULHHTmcXijmRmQE37+3Y7BSx05fDtQdiG8pPg5OUk3PZO9eYQ3 rHzTajf2b2TY8diSWy4Q305Nvp6zBAcEOC3/UruczIw/+Ai2BMbo4ssEc w==; X-IronPort-AV: E=Sophos;i="5.97,313,1669071600"; d="scan'208";a="29196106" Received: from unknown (HELO tq-pgp-pr1.tq-net.de) ([192.168.6.15]) by mx1-pgp.tq-group.com with ESMTP; 20 Feb 2023 17:17:38 +0100 Received: from mx1.tq-group.com ([192.168.6.7]) by tq-pgp-pr1.tq-net.de (PGP Universal service); Mon, 20 Feb 2023 17:17:38 +0100 X-PGP-Universal: processed; by tq-pgp-pr1.tq-net.de on Mon, 20 Feb 2023 17:17:38 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tq-group.com; i=@tq-group.com; q=dns/txt; s=key1; t=1676909858; x=1708445858; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=m8U/qv7GUyyJtoJ/cmMrOe+OYej/LgVV8kl3LQxG2EQ=; b=Lk/q+IZjSFrI/5NiWKV0J0Zp23BAbN2iLfGv+ssgKvprEbkYJg2+8v7W QbcEcbOGdjo25bYpYuBUutZdMh4e7Vdi627XUfgOYAX08XjPjihvZXFOK l8Zd4oMXjT3E1KIJxbZ/CI5GXmtji1tuAucWIB18QEP5e2xX4NqCeLvwf bHrCEWvgIkUdkZTbH8Oel0MQyedc952xIbF1YhiPgJ9T5k2gNtePiphqG O86GdDL5zfkR7+qrMZratlzaLpNE7RGPY7ieYBJ2I4ko0Vz4Y05gzb/LG td5I8Kc7E+dWu5AseV/I5YANhoQzVBy0sh9un4KeOoFg8tO2gYm4YnDnz w==; X-IronPort-AV: E=Sophos;i="5.97,313,1669071600"; d="scan'208";a="29196105" Received: from vtuxmail01.tq-net.de ([10.115.0.20]) by mx1.tq-group.com with ESMTP; 20 Feb 2023 17:17:38 +0100 Received: from localhost.localdomain (SCHIFFERM-M2.tq-net.de [10.121.49.14]) by vtuxmail01.tq-net.de (Postfix) with ESMTPA id BDA7C280056; Mon, 20 Feb 2023 17:17:37 +0100 (CET) From: Matthias Schiffer To: Peter Korsgaard , Andrew Lunn Cc: Federico Vaga , Wolfram Sang , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, linux@ew.tq-group.com Subject: [PATCH] i2c: ocores: generate stop condition after timeout in polling mode Date: Mon, 20 Feb 2023 17:16:28 +0100 Message-Id: <20230220161628.463620-1-matthias.schiffer@ew.tq-group.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org From: Gregor Herburger In polling mode, no stop condition is generated after a timeout. This causes SCL to remain low and thereby block the bus. If this happens during a transfer it can cause slaves to misinterpret the subsequent transfer and return wrong values. To solve this, pass the ETIMEDOUT error up from ocores_process_polling() instead of setting STATE_ERROR directly. The caller is adjusted to call ocores_process_timeout() on error both in polling and in IRQ mode, which will set STATE_ERROR and generate a stop condition. Fixes: 69c8c0c0efa8 ("i2c: ocores: add polling interface") Signed-off-by: Gregor Herburger Signed-off-by: Matthias Schiffer --- drivers/i2c/busses/i2c-ocores.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c index a0af027db04c1..28bcda3f7040a 100644 --- a/drivers/i2c/busses/i2c-ocores.c +++ b/drivers/i2c/busses/i2c-ocores.c @@ -342,18 +342,18 @@ static int ocores_poll_wait(struct ocores_i2c *i2c) * ocores_isr(), we just add our polling code around it. * * It can run in atomic context + * + * Return: 0 on success, -ETIMEDOUT on timeout */ -static void ocores_process_polling(struct ocores_i2c *i2c) +static int ocores_process_polling(struct ocores_i2c *i2c) { while (1) { irqreturn_t ret; int err; err = ocores_poll_wait(i2c); - if (err) { - i2c->state = STATE_ERROR; - break; /* timeout */ - } + if (err) + return err; ret = ocores_isr(-1, i2c); if (ret == IRQ_NONE) @@ -364,6 +364,8 @@ static void ocores_process_polling(struct ocores_i2c *i2c) break; } } + + return 0; } static int ocores_xfer_core(struct ocores_i2c *i2c, @@ -387,16 +389,16 @@ static int ocores_xfer_core(struct ocores_i2c *i2c, oc_setreg(i2c, OCI2C_DATA, i2c_8bit_addr_from_msg(i2c->msg)); oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_START); - if (polling) { - ocores_process_polling(i2c); - } else { + if (polling) + ret = ocores_process_polling(i2c); + else ret = wait_event_timeout(i2c->wait, (i2c->state == STATE_ERROR) || - (i2c->state == STATE_DONE), HZ); - if (ret == 0) { - ocores_process_timeout(i2c); - return -ETIMEDOUT; - } + (i2c->state == STATE_DONE), HZ) ? + 0 : -ETIMEDOUT; + if (ret) { + ocores_process_timeout(i2c); + return ret; } return (i2c->state == STATE_DONE) ? num : -EIO;