From patchwork Wed Oct 9 21:20:34 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jae Hyun Yoo X-Patchwork-Id: 11182205 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C99DC1668 for ; Wed, 9 Oct 2019 21:20:40 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A7D4221929 for ; Wed, 9 Oct 2019 21:20:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="e+OmdpYQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A7D4221929 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=azYxSBMjczGbgUckLFpQOx50mUyBTM6wa5zISS//ymI=; b=e+OmdpYQO9JIi7 tmJeI2VEYZloyplkA60byZkrnWU3rSOhC0tGXqLb2I9ChHPzfBXO1R1wcHSCgofobLjleOl8oHif5 XDHn8jE8YforrLQGkbegMeZKQcTshPwLsrkgDpHw9AiRSiex/YcX5CGWBbdJfW/dn6iCDgBPFcUiz dvdKrxUOmF6eEztmEiwID1E05AduS4TF855kdDWAJNi6L4sPIlTUslQWZPfo1UccDRChxlJ+/Q4yn S1jVTh48f1nBvlVTzbs90SfTLGlGgi51uFl0hULMWN7+ZcKohzrePe0VahuEXPcnRmoqJIMn5naTY ZDiKDk3J268okNa2rh0g==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iIJNw-0003Pj-87; Wed, 09 Oct 2019 21:20:40 +0000 Received: from mga14.intel.com ([192.55.52.115]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1iIJNs-0003PG-So for linux-arm-kernel@lists.infradead.org; Wed, 09 Oct 2019 21:20:38 +0000 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 Oct 2019 14:20:35 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.67,277,1566889200"; d="scan'208";a="368866255" Received: from maru.jf.intel.com ([10.54.51.77]) by orsmga005.jf.intel.com with ESMTP; 09 Oct 2019 14:20:35 -0700 From: Jae Hyun Yoo To: Brendan Higgins , Wolfram Sang , Benjamin Herrenschmidt , Joel Stanley , Rob Herring , Mark Rutland , Andrew Jeffery , Tao Ren , Cedric Le Goater Subject: [PATCH] i2c: aspeed: fix master pending state handling Date: Wed, 9 Oct 2019 14:20:34 -0700 Message-Id: <20191009212034.20325-1-jae.hyun.yoo@linux.intel.com> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191009_142036_944982_C2CB4F9E X-CRM114-Status: GOOD ( 21.00 ) X-Spam-Score: -2.6 (--) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-2.6 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at https://www.dnswl.org/, high trust [192.55.52.115 listed in list.dnswl.org] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 0.0 SPF_NONE SPF: sender does not publish an SPF Record 2.4 AC_FROM_MANY_DOTS Multiple periods in From user name X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, Jae Hyun Yoo , linux-aspeed@lists.ozlabs.org, openbmc@lists.ozlabs.org, linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org In case of master pending state, it should not trigger a master command, otherwise data could be corrupted because this H/W shares the same data buffer for slave and master operations. It also means that H/W command queue handling is unreliable because of the buffer sharing issue. To fix this issue, it clears command queue if a master command is queued in pending state to use S/W solution instead of H/W command queue handling. Also, it refines restarting mechanism of the pending master command. Fixes: 2e57b7cebb98 ("i2c: aspeed: Add multi-master use case support") Signed-off-by: Jae Hyun Yoo Reviewed-by: Brendan Higgins Acked-by: Joel Stanley Tested-by: Tao Ren --- drivers/i2c/busses/i2c-aspeed.c | 54 +++++++++++++++++++++------------ 1 file changed, 34 insertions(+), 20 deletions(-) diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c index fa66951b05d0..7b098ff5f5dd 100644 --- a/drivers/i2c/busses/i2c-aspeed.c +++ b/drivers/i2c/busses/i2c-aspeed.c @@ -108,6 +108,12 @@ #define ASPEED_I2CD_S_TX_CMD BIT(2) #define ASPEED_I2CD_M_TX_CMD BIT(1) #define ASPEED_I2CD_M_START_CMD BIT(0) +#define ASPEED_I2CD_MASTER_CMDS_MASK \ + (ASPEED_I2CD_M_STOP_CMD | \ + ASPEED_I2CD_M_S_RX_CMD_LAST | \ + ASPEED_I2CD_M_RX_CMD | \ + ASPEED_I2CD_M_TX_CMD | \ + ASPEED_I2CD_M_START_CMD) /* 0x18 : I2CD Slave Device Address Register */ #define ASPEED_I2CD_DEV_ADDR_MASK GENMASK(6, 0) @@ -336,18 +342,19 @@ static void aspeed_i2c_do_start(struct aspeed_i2c_bus *bus) struct i2c_msg *msg = &bus->msgs[bus->msgs_index]; u8 slave_addr = i2c_8bit_addr_from_msg(msg); - bus->master_state = ASPEED_I2C_MASTER_START; - #if IS_ENABLED(CONFIG_I2C_SLAVE) /* * If it's requested in the middle of a slave session, set the master * state to 'pending' then H/W will continue handling this master * command when the bus comes back to the idle state. */ - if (bus->slave_state != ASPEED_I2C_SLAVE_INACTIVE) + if (bus->slave_state != ASPEED_I2C_SLAVE_INACTIVE) { bus->master_state = ASPEED_I2C_MASTER_PENDING; + return; + } #endif /* CONFIG_I2C_SLAVE */ + bus->master_state = ASPEED_I2C_MASTER_START; bus->buf_index = 0; if (msg->flags & I2C_M_RD) { @@ -422,20 +429,6 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) } } -#if IS_ENABLED(CONFIG_I2C_SLAVE) - /* - * A pending master command will be started by H/W when the bus comes - * back to idle state after completing a slave operation so change the - * master state from 'pending' to 'start' at here if slave is inactive. - */ - if (bus->master_state == ASPEED_I2C_MASTER_PENDING) { - if (bus->slave_state != ASPEED_I2C_SLAVE_INACTIVE) - goto out_no_complete; - - bus->master_state = ASPEED_I2C_MASTER_START; - } -#endif /* CONFIG_I2C_SLAVE */ - /* Master is not currently active, irq was for someone else. */ if (bus->master_state == ASPEED_I2C_MASTER_INACTIVE || bus->master_state == ASPEED_I2C_MASTER_PENDING) @@ -462,11 +455,15 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) #if IS_ENABLED(CONFIG_I2C_SLAVE) /* * If a peer master starts a xfer immediately after it queues a - * master command, change its state to 'pending' then H/W will - * continue the queued master xfer just after completing the - * slave mode session. + * master command, clear the queued master command and change + * its state to 'pending'. To simplify handling of pending + * cases, it uses S/W solution instead of H/W command queue + * handling. */ if (unlikely(irq_status & ASPEED_I2CD_INTR_SLAVE_MATCH)) { + writel(readl(bus->base + ASPEED_I2C_CMD_REG) & + ~ASPEED_I2CD_MASTER_CMDS_MASK, + bus->base + ASPEED_I2C_CMD_REG); bus->master_state = ASPEED_I2C_MASTER_PENDING; dev_dbg(bus->dev, "master goes pending due to a slave start\n"); @@ -629,6 +626,14 @@ static irqreturn_t aspeed_i2c_bus_irq(int irq, void *dev_id) irq_handled |= aspeed_i2c_master_irq(bus, irq_remaining); } + + /* + * Start a pending master command at here if a slave operation is + * completed. + */ + if (bus->master_state == ASPEED_I2C_MASTER_PENDING && + bus->slave_state == ASPEED_I2C_SLAVE_INACTIVE) + aspeed_i2c_do_start(bus); #else irq_handled = aspeed_i2c_master_irq(bus, irq_remaining); #endif /* CONFIG_I2C_SLAVE */ @@ -691,6 +696,15 @@ static int aspeed_i2c_master_xfer(struct i2c_adapter *adap, ASPEED_I2CD_BUS_BUSY_STS)) aspeed_i2c_recover_bus(bus); + /* + * If timed out and the state is still pending, drop the pending + * master command. + */ + spin_lock_irqsave(&bus->lock, flags); + if (bus->master_state == ASPEED_I2C_MASTER_PENDING) + bus->master_state = ASPEED_I2C_MASTER_INACTIVE; + spin_unlock_irqrestore(&bus->lock, flags); + return -ETIMEDOUT; }