From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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=-15.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 9BC7DC43381 for ; Mon, 11 Jan 2021 15:53:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5298C22AAF for ; Mon, 11 Jan 2021 15:53:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388458AbhAKPxC (ORCPT ); Mon, 11 Jan 2021 10:53:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733284AbhAKPxB (ORCPT ); Mon, 11 Jan 2021 10:53:01 -0500 Received: from mail.kapsi.fi (mail.kapsi.fi [IPv6:2001:67c:1be8::25]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 345C6C061786; Mon, 11 Jan 2021 07:52:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=kapsi.fi; s=20161220; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=NqDVkTYbg8Kl34pjG1mAKbMpd/CjudU1qP8KEuOj/+Y=; b=T1FBeHz3xwT+m9t5JqWfKv+TZf YORCE9GpHgX/hYQtv8n1+LlBF5TE0BUgA0k9zO1WAyenVmN2BM8P+/2LUtJs2sXwwavfliXNsKBDZ 9b1Ya0IrAm61d7L2wx2TY/jd8Ca1l2qqP0KUGubyJnTsrB4QCq5rmgnEIHLic7IG5hU0wjIVAUGWd DcnfU9ZF6Cu6ctvvHTW/8qRPAvjThl5dN5oN0EJ4DVk260Q+Kg1ESYCk034x+APiQha9q1GFcn698 46+3jTp+4wEzsRFJDT7+XzaDYbxq+epZNefRA0uYU8o0y6BCJ3cQLOACEV59wc+3qWL4x4MLhW9QP /7rc9TxQ==; Received: from dsl-hkibng22-54f986-236.dhcp.inet.fi ([84.249.134.236] helo=[192.168.1.10]) by mail.kapsi.fi with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89) (envelope-from ) id 1kyzUR-0004Sw-Np; Mon, 11 Jan 2021 17:52:19 +0200 Subject: Re: [PATCH] i2c: tegra: Wait for config load atomically while in ISR To: Dmitry Osipenko , Mikko Perttunen , ldewangan@nvidia.com, thierry.reding@gmail.com, jonathanh@nvidia.com, wsa@kernel.org Cc: linux-i2c@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20210111135547.3613092-1-mperttunen@nvidia.com> From: Mikko Perttunen Message-ID: Date: Mon, 11 Jan 2021 17:52:19 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 84.249.134.236 X-SA-Exim-Mail-From: cyndis@kapsi.fi X-SA-Exim-Scanned: No (on mail.kapsi.fi); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org On 1/11/21 5:14 PM, Dmitry Osipenko wrote: > 11.01.2021 16:55, Mikko Perttunen пишет: >> Upon a communication error, the interrupt handler can call >> tegra_i2c_disable_packet_mode. This causes a sleeping poll to happen >> unless the current transaction was marked atomic. Since >> tegra_i2c_disable_packet_mode is only called from the interrupt path, >> make it use atomic waiting always. >> >> Fixes: ede2299f7101 ("i2c: tegra: Support atomic transfers") >> Cc: stable@vger.kernel.org >> Signed-off-by: Mikko Perttunen >> --- >> This fixes constant spew for me while HDMI is connected to a >> powered off television. >> >> drivers/i2c/busses/i2c-tegra.c | 16 ++++++++-------- >> 1 file changed, 8 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c >> index 6f08c0c3238d..4a7ff1840565 100644 >> --- a/drivers/i2c/busses/i2c-tegra.c >> +++ b/drivers/i2c/busses/i2c-tegra.c >> @@ -528,12 +528,12 @@ static void tegra_i2c_vi_init(struct tegra_i2c_dev *i2c_dev) >> >> static int tegra_i2c_poll_register(struct tegra_i2c_dev *i2c_dev, >> u32 reg, u32 mask, u32 delay_us, >> - u32 timeout_us) >> + u32 timeout_us, bool force_atomic) >> { >> void __iomem *addr = i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg); >> u32 val; >> >> - if (!i2c_dev->atomic_mode) >> + if (!i2c_dev->atomic_mode && !force_atomic) >> return readl_relaxed_poll_timeout(addr, val, !(val & mask), >> delay_us, timeout_us); >> >> @@ -560,7 +560,7 @@ static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev) >> val |= mask; >> i2c_writel(i2c_dev, val, offset); >> >> - err = tegra_i2c_poll_register(i2c_dev, offset, mask, 1000, 1000000); >> + err = tegra_i2c_poll_register(i2c_dev, offset, mask, 1000, 1000000, false); >> if (err) { >> dev_err(i2c_dev->dev, "failed to flush FIFO\n"); >> return err; >> @@ -569,7 +569,7 @@ static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev) >> return 0; >> } >> >> -static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev) >> +static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev, bool force_atomic) >> { >> int err; >> >> @@ -579,7 +579,7 @@ static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev) >> i2c_writel(i2c_dev, I2C_MSTR_CONFIG_LOAD, I2C_CONFIG_LOAD); >> >> err = tegra_i2c_poll_register(i2c_dev, I2C_CONFIG_LOAD, 0xffffffff, >> - 1000, I2C_CONFIG_LOAD_TIMEOUT); >> + 1000, I2C_CONFIG_LOAD_TIMEOUT, force_atomic); >> if (err) { >> dev_err(i2c_dev->dev, "failed to load config\n"); >> return err; >> @@ -684,7 +684,7 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev) >> if (i2c_dev->multimaster_mode && i2c_dev->hw->has_slcg_override_reg) >> i2c_writel(i2c_dev, I2C_MST_CORE_CLKEN_OVR, I2C_CLKEN_OVERRIDE); >> >> - err = tegra_i2c_wait_for_config_load(i2c_dev); >> + err = tegra_i2c_wait_for_config_load(i2c_dev, false); >> if (err) >> return err; >> >> @@ -707,7 +707,7 @@ static int tegra_i2c_disable_packet_mode(struct tegra_i2c_dev *i2c_dev) >> if (cnfg & I2C_CNFG_PACKET_MODE_EN) >> i2c_writel(i2c_dev, cnfg & ~I2C_CNFG_PACKET_MODE_EN, I2C_CNFG); >> >> - return tegra_i2c_wait_for_config_load(i2c_dev); >> + return tegra_i2c_wait_for_config_load(i2c_dev, true); >> } >> >> static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev) >> @@ -1090,7 +1090,7 @@ static int tegra_i2c_issue_bus_clear(struct i2c_adapter *adap) >> I2C_BC_TERMINATE; >> i2c_writel(i2c_dev, val, I2C_BUS_CLEAR_CNFG); >> >> - err = tegra_i2c_wait_for_config_load(i2c_dev); >> + err = tegra_i2c_wait_for_config_load(i2c_dev, false); >> if (err) >> return err; >> >> > > What about a simpler variant: > > diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c > index 6f08c0c3238d..0727383f4940 100644 > --- a/drivers/i2c/busses/i2c-tegra.c > +++ b/drivers/i2c/busses/i2c-tegra.c > @@ -533,7 +533,7 @@ static int tegra_i2c_poll_register(struct > tegra_i2c_dev *i2c_dev, > void __iomem *addr = i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg); > u32 val; > > - if (!i2c_dev->atomic_mode) > + if (!i2c_dev->atomic_mode && !in_irq()) > return readl_relaxed_poll_timeout(addr, val, !(val & mask), > delay_us, timeout_us); > Yep, I'll post a v2 with that. Mikko