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=-12.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,MIME_HEADER_CTYPE_ONLY,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,T_TVD_MIME_NO_HEADERS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 10D09C43457 for ; Sun, 11 Oct 2020 18:24:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CC2D72222C for ; Sun, 11 Oct 2020 18:24:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="LriUnQOL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728741AbgJKSYL (ORCPT ); Sun, 11 Oct 2020 14:24:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50840 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728654AbgJKSYK (ORCPT ); Sun, 11 Oct 2020 14:24:10 -0400 Received: from mail-pf1-x444.google.com (mail-pf1-x444.google.com [IPv6:2607:f8b0:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 49801C0613CE for ; Sun, 11 Oct 2020 11:24:10 -0700 (PDT) Received: by mail-pf1-x444.google.com with SMTP id e7so2324248pfn.12 for ; Sun, 11 Oct 2020 11:24:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=RhRTVGLwMlh2VV6dvWs6BmoKc1nFs8ftRSOLRr9Wvtw=; b=LriUnQOLsxVK6KHg6Hj/y1wyCwU6XUOuo05JfquCoAE/zIDtOKxMH8N+U8tU8wUl3d U46Vxs9YfLgmLe0VZDTQsr8qPohrtLIHI4TTzyJy+wBLVuCICLsMk6mVWRRXfz2NTE/Z AsnGSIqeLjEEw74f9dxL52IqQUFgptLUHdnh0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=RhRTVGLwMlh2VV6dvWs6BmoKc1nFs8ftRSOLRr9Wvtw=; b=A6eHUUgc19VUsafi5q8nPJyupuNND2ieoonOP47Uh+vnDAAoy7i3so9wIXC7uSdYoj W44lOIIAtWqUHf3tuv+pqk4YdkY0IDHROS2LOXmAirkYiD6lNkrSDOA83wzI4He67J+r vL9nOUxSLk5yWLq5rHO62wbAc6t+pn4An2xehQpnEU5YmmaGGJehEZ90Cg3qfC/4p0bO jY2z7nibn2ogiq8EbDRGwT9b+onAyUvoDeAECYJ8rRsx/w9zxrZ48CSwv2JtiSul/yGg XUz4bnzsYBo7bIm4LUWm0qX4B4U/RUgIXjKAotKJvfo9u8b1Tg69+ONcl+OsgrdCLQ8Y g6YA== X-Gm-Message-State: AOAM5311AZlLR0iQg71ZIdgLKFLTQ0dFp7lGo73i/T4pMYcOIAsd/t0p vxw1TLQLtUwGfE0Xq8Izaq1Oiw== X-Google-Smtp-Source: ABdhPJxjqJEt4ZIII9dcTR8qfMSvBlv8jI3OBCkW4g45W0sHiVbrznvCOoz2STsZgpv2Xswh4QPaGw== X-Received: by 2002:a17:90a:d80e:: with SMTP id a14mr15875676pjv.168.1602440649673; Sun, 11 Oct 2020 11:24:09 -0700 (PDT) Received: from rayagonda.dhcp.broadcom.net ([192.19.234.250]) by smtp.gmail.com with ESMTPSA id g1sm21977807pjj.3.2020.10.11.11.24.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 11 Oct 2020 11:24:09 -0700 (PDT) From: Rayagonda Kokatanur To: Ray Jui , Scott Branden , bcm-kernel-feedback-list@broadcom.com, Wolfram Sang , Florian Fainelli , Brendan Higgins , Andy Shevchenko , Lori Hikichi , Dhananjay Phadke , linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Rayagonda Kokatanur Subject: [PATCH v1 6/6] i2c: iproc: handle rx fifo full interrupt Date: Sun, 11 Oct 2020 23:52:54 +0530 Message-Id: <20201011182254.17776-7-rayagonda.kokatanur@broadcom.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201011182254.17776-1-rayagonda.kokatanur@broadcom.com> References: <20201011182254.17776-1-rayagonda.kokatanur@broadcom.com> Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha-256; boundary="000000000000b8f85505b169496d" Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org --000000000000b8f85505b169496d Add code to handle IS_S_RX_FIFO_FULL_SHIFT interrupt to support master write request with >= 64 bytes. Iproc has a slave rx fifo size of 64 bytes. Rx fifo full interrupt (IS_S_RX_FIFO_FULL_SHIFT) will be generated when RX fifo becomes full. This can happen if master issues write request of more than 64 bytes. Signed-off-by: Rayagonda Kokatanur --- drivers/i2c/busses/i2c-bcm-iproc.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c index 22e04055b447..cceaf69279a9 100644 --- a/drivers/i2c/busses/i2c-bcm-iproc.c +++ b/drivers/i2c/busses/i2c-bcm-iproc.c @@ -313,6 +313,8 @@ static void bcm_iproc_i2c_slave_init( /* Enable interrupt register to indicate a valid byte in receive fifo */ val = BIT(IE_S_RX_EVENT_SHIFT); + /* Enable interrupt register to indicate Slave Rx FIFO Full */ + val |= BIT(IE_S_RX_FIFO_FULL_SHIFT); /* Enable interrupt register to indicate a Master read transaction */ val |= BIT(IE_S_RD_EVENT_SHIFT); /* Enable interrupt register for the Slave BUSY command */ @@ -434,9 +436,15 @@ static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c, * events * Master-read : both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT * events or only IS_S_RD_EVENT_SHIFT + * + * iproc has a slave rx fifo size of 64 bytes. Rx fifo full interrupt + * (IS_S_RX_FIFO_FULL_SHIFT) will be generated when RX fifo becomes + * full. This can happen if Master issues write requests of more than + * 64 bytes. */ if (status & BIT(IS_S_RX_EVENT_SHIFT) || - status & BIT(IS_S_RD_EVENT_SHIFT)) { + status & BIT(IS_S_RD_EVENT_SHIFT) || + status & BIT(IS_S_RX_FIFO_FULL_SHIFT)) { /* disable slave interrupts */ val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); val &= ~iproc_i2c->slave_int_mask; @@ -452,9 +460,14 @@ static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c, /* schedule tasklet to read data later */ tasklet_schedule(&iproc_i2c->slave_rx_tasklet); - /* clear only IS_S_RX_EVENT_SHIFT interrupt */ - iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, - BIT(IS_S_RX_EVENT_SHIFT)); + /* + * clear only IS_S_RX_EVENT_SHIFT and + * IS_S_RX_FIFO_FULL_SHIFT interrupt. + */ + val = BIT(IS_S_RX_EVENT_SHIFT); + if (status & BIT(IS_S_RX_FIFO_FULL_SHIFT)) + val |= BIT(IS_S_RX_FIFO_FULL_SHIFT); + iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, val); } if (status & BIT(IS_S_TX_UNDERRUN_SHIFT)) { -- 2.17.1 --000000000000b8f85505b169496d 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linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, lori.hikichi@broadcom.com, rjui@broadcom.com, sbranden@broadcom.com, wsa@kernel.org Subject: [PATCH v1 6/6] i2c: iproc: handle rx fifo full interrupt Date: Mon, 12 Oct 2020 15:03:04 -0700 Message-ID: <20201011182254.17776-7-rayagonda.kokatanur@broadcom.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <20201011182254.17776-7-rayagonda.kokatanur@broadcom.com> References: <20201011182254.17776-7-rayagonda.kokatanur@broadcom.com> Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Message-ID: <20201012220304.oBt3wutbEhjjmEuAaCnt6wB6oMGnz3w08PrfgyLAwug@z> From: Rayagonda Kokatanur On Sun, 11 Oct 2020 23:52:54 +0530, Rayagonda Kokatanur wrote: > Add code to handle IS_S_RX_FIFO_FULL_SHIFT interrupt to support > master write request with >= 64 bytes. > > Iproc has a slave rx fifo size of 64 bytes. > Rx fifo full interrupt (IS_S_RX_FIFO_FULL_SHIFT) will be generated > when RX fifo becomes full. This can happen if master issues write > request of more than 64 bytes. > ARM cores run much faster than I2C bus, why would rx fifo go full when rx interrupt is enabled and bytes are read out by bus driver isr? Isn't fifo read pointer updated on these byte reads? Does controller stretch clock when rx fifo is full (e.g. kernel has crashed, bus driver isn't draining fifo)?