From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 0EB752566 for ; Tue, 18 Apr 2023 12:32:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 85033C4339C; Tue, 18 Apr 2023 12:32:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681821121; bh=g1JdaTqc+GJwXQHupKB9cJr+LsSeKB6hTeeliZTCv5g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VYu+/sxmRH8rab+uMucgOA8z6V3yujokpF61mvATO9Tut2/Bn7j7IDxn69F2tdS4b btCh7N9DOrqH1wctOuib1Ii/tsXAEB3OUIXKgaDGt/qLEznyIMGxpm0JPFOvBbfkEp bPcLbEePIED7Y1fAvVAdFz/o5is4PlKpN1Y7nI3s= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Gregor Herburger , Matthias Schiffer , Peter Korsgaard , Andrew Lunn , Federico Vaga , Wolfram Sang , Sasha Levin Subject: [PATCH 5.4 73/92] i2c: ocores: generate stop condition after timeout in polling mode Date: Tue, 18 Apr 2023 14:21:48 +0200 Message-Id: <20230418120307.347576921@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230418120304.658273364@linuxfoundation.org> References: <20230418120304.658273364@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Gregor Herburger [ Upstream commit f8160d3b35fc94491bb0cb974dbda310ef96c0e2 ] 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 Acked-by: Peter Korsgaard Reviewed-by: Andrew Lunn Reviewed-by: Federico Vaga Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/busses/i2c-ocores.c | 35 ++++++++++++++++++--------------- 1 file changed, 19 insertions(+), 16 deletions(-) diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c index ca8b3ecfa93d1..1c3595c8a761a 100644 --- a/drivers/i2c/busses/i2c-ocores.c +++ b/drivers/i2c/busses/i2c-ocores.c @@ -343,18 +343,18 @@ 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; + irqreturn_t ret; + int err = 0; + while (1) { err = ocores_poll_wait(i2c); - if (err) { - i2c->state = STATE_ERROR; + if (err) break; /* timeout */ - } ret = ocores_isr(-1, i2c); if (ret == IRQ_NONE) @@ -365,13 +365,15 @@ static void ocores_process_polling(struct ocores_i2c *i2c) break; } } + + return err; } static int ocores_xfer_core(struct ocores_i2c *i2c, struct i2c_msg *msgs, int num, bool polling) { - int ret; + int ret = 0; u8 ctrl; ctrl = oc_getreg(i2c, OCI2C_CONTROL); @@ -389,15 +391,16 @@ static int ocores_xfer_core(struct ocores_i2c *i2c, oc_setreg(i2c, OCI2C_CMD, OCI2C_CMD_START); if (polling) { - ocores_process_polling(i2c); + 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; - } + if (wait_event_timeout(i2c->wait, + (i2c->state == STATE_ERROR) || + (i2c->state == STATE_DONE), HZ) == 0) + ret = -ETIMEDOUT; + } + if (ret) { + ocores_process_timeout(i2c); + return ret; } return (i2c->state == STATE_DONE) ? num : -EIO; -- 2.39.2