From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:53568 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752829AbdBUNEe (ORCPT ); Tue, 21 Feb 2017 08:04:34 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Shah Nehal-Bakulchandra , Suravee Suthikulpanit , Lucas De Marchi , Jarkko Nikula , Wolfram Sang Subject: [PATCH 4.9 14/22] Revert "i2c: designware: detect when dynamic tar update is possible" Date: Tue, 21 Feb 2017 14:03:28 +0100 Message-Id: <20170221130219.519645022@linuxfoundation.org> In-Reply-To: <20170221130218.888428471@linuxfoundation.org> References: <20170221130218.888428471@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jarkko Nikula commit 12688dc21f71f4dcc9e2b8b5556b0c6cc8df1491 upstream. This reverts commit 63d0f0a6952a1a02bc4f116b7da7c7887e46efa3. It caused a regression on platforms where I2C controller is synthesized with dynamic TAR update disabled. Detection code is testing is bit DW_IC_CON_10BITADDR_MASTER in register DW_IC_CON read-only but fails to restore original value in case bit is read-write. Instead of fixing this we revert the commit since it was preparation for the commit 0317e6c0f1dc ("i2c: designware: do not disable adapter after transfer") which was also reverted. Reported-by: Shah Nehal-Bakulchandra Reported-by: Suravee Suthikulpanit Acked-By: Lucas De Marchi Fixes: 63d0f0a6952a ("i2c: designware: detect when dynamic tar update is possible") Signed-off-by: Jarkko Nikula Signed-off-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman --- drivers/i2c/busses/i2c-designware-core.c | 45 +++++++------------------------ drivers/i2c/busses/i2c-designware-core.h | 1 2 files changed, 11 insertions(+), 35 deletions(-) --- a/drivers/i2c/busses/i2c-designware-core.c +++ b/drivers/i2c/busses/i2c-designware-core.c @@ -475,30 +475,28 @@ static int i2c_dw_wait_bus_not_busy(stru static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) { struct i2c_msg *msgs = dev->msgs; - u32 ic_tar = 0; + u32 ic_con, ic_tar = 0; /* Disable the adapter */ __i2c_dw_enable_and_wait(dev, false); /* if the slave address is ten bit address, enable 10BITADDR */ - if (dev->dynamic_tar_update_enabled) { + ic_con = dw_readl(dev, DW_IC_CON); + if (msgs[dev->msg_write_idx].flags & I2C_M_TEN) { + ic_con |= DW_IC_CON_10BITADDR_MASTER; /* * If I2C_DYNAMIC_TAR_UPDATE is set, the 10-bit addressing - * mode has to be enabled via bit 12 of IC_TAR register, - * otherwise bit 4 of IC_CON is used. + * mode has to be enabled via bit 12 of IC_TAR register. + * We set it always as I2C_DYNAMIC_TAR_UPDATE can't be + * detected from registers. */ - if (msgs[dev->msg_write_idx].flags & I2C_M_TEN) - ic_tar = DW_IC_TAR_10BITADDR_MASTER; + ic_tar = DW_IC_TAR_10BITADDR_MASTER; } else { - u32 ic_con = dw_readl(dev, DW_IC_CON); - - if (msgs[dev->msg_write_idx].flags & I2C_M_TEN) - ic_con |= DW_IC_CON_10BITADDR_MASTER; - else - ic_con &= ~DW_IC_CON_10BITADDR_MASTER; - dw_writel(dev, ic_con, DW_IC_CON); + ic_con &= ~DW_IC_CON_10BITADDR_MASTER; } + dw_writel(dev, ic_con, DW_IC_CON); + /* * Set the slave (target) address and enable 10-bit addressing mode * if applicable. @@ -923,7 +921,6 @@ int i2c_dw_probe(struct dw_i2c_dev *dev) { struct i2c_adapter *adap = &dev->adapter; int r; - u32 reg; init_completion(&dev->cmd_complete); @@ -931,26 +928,6 @@ int i2c_dw_probe(struct dw_i2c_dev *dev) if (r) return r; - r = i2c_dw_acquire_lock(dev); - if (r) - return r; - - /* - * Test if dynamic TAR update is enabled in this controller by writing - * to IC_10BITADDR_MASTER field in IC_CON: when it is enabled this - * field is read-only so it should not succeed - */ - reg = dw_readl(dev, DW_IC_CON); - dw_writel(dev, reg ^ DW_IC_CON_10BITADDR_MASTER, DW_IC_CON); - - if ((dw_readl(dev, DW_IC_CON) & DW_IC_CON_10BITADDR_MASTER) == - (reg & DW_IC_CON_10BITADDR_MASTER)) { - dev->dynamic_tar_update_enabled = true; - dev_dbg(dev->dev, "Dynamic TAR update enabled"); - } - - i2c_dw_release_lock(dev); - snprintf(adap->name, sizeof(adap->name), "Synopsys DesignWare I2C adapter"); adap->retries = 3; --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -117,7 +117,6 @@ struct dw_i2c_dev { int (*acquire_lock)(struct dw_i2c_dev *dev); void (*release_lock)(struct dw_i2c_dev *dev); bool pm_runtime_disabled; - bool dynamic_tar_update_enabled; }; #define ACCESS_SWAP 0x00000001