From patchwork Thu Feb 25 14:26:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?5Lmx55+z?= X-Patchwork-Id: 387437 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY, 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 A2AC3C433E0 for ; Thu, 25 Feb 2021 14:27:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4491564F11 for ; Thu, 25 Feb 2021 14:27:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229722AbhBYO1i (ORCPT ); Thu, 25 Feb 2021 09:27:38 -0500 Received: from out30-43.freemail.mail.aliyun.com ([115.124.30.43]:54627 "EHLO out30-43.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229507AbhBYO1h (ORCPT ); Thu, 25 Feb 2021 09:27:37 -0500 X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R841e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=e01e01424; MF=zhangliguang@linux.alibaba.com; NM=1; PH=DS; RN=7; SR=0; TI=SMTPD_---0UPYnEh._1614263193; Received: from localhost(mailfrom:zhangliguang@linux.alibaba.com fp:SMTPD_---0UPYnEh._1614263193) by smtp.aliyun-inc.com(127.0.0.1); Thu, 25 Feb 2021 22:26:41 +0800 From: Liguang Zhang To: Jarkko Nikula , Andy Shevchenko , Mika Westerberg , Philipp Zabel Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Liguang Zhang Subject: [PATCH v2] i2c: designware: Get right data length Date: Thu, 25 Feb 2021 22:26:31 +0800 Message-Id: <20210225142631.1882-1-zhangliguang@linux.alibaba.com> X-Mailer: git-send-email 2.19.1.6.gb485710b MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org IC_DATA_CMD[11] indicates the first data byte received after the address phase for receive transfer in Master receiver or Slave receiver mode, this bit was set in some transfer flow. IC_DATA_CMD[7:0] contains the data to be transmitted or received on the I2C bus, so we should use the lower 8 bits to get the real data length. Signed-off-by: Liguang Zhang Reviewed-by: Andy Shevchenko --- drivers/i2c/busses/i2c-designware-core.h | 2 ++ drivers/i2c/busses/i2c-designware-master.c | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h index 85307cfa7109..5392b82f68a4 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -38,6 +38,8 @@ #define DW_IC_CON_TX_EMPTY_CTRL BIT(8) #define DW_IC_CON_RX_FIFO_FULL_HLD_CTRL BIT(9) +#define DW_IC_DATA_CMD_DAT GENMASK(7, 0) + /* * Registers offset */ diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c index d6425ad6e6a3..dd27b9dbe931 100644 --- a/drivers/i2c/busses/i2c-designware-master.c +++ b/drivers/i2c/busses/i2c-designware-master.c @@ -432,7 +432,7 @@ i2c_dw_read(struct dw_i2c_dev *dev) regmap_read(dev->map, DW_IC_DATA_CMD, &tmp); /* Ensure length byte is a valid value */ if (flags & I2C_M_RECV_LEN && - tmp <= I2C_SMBUS_BLOCK_MAX && tmp > 0) { + (tmp & DW_IC_DATA_CMD_DAT) <= I2C_SMBUS_BLOCK_MAX && tmp > 0) { len = i2c_dw_recv_len(dev, tmp); } *buf++ = tmp;