From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753102AbcFJKnt (ORCPT ); Fri, 10 Jun 2016 06:43:49 -0400 Received: from mail-oi0-f66.google.com ([209.85.218.66]:36691 "EHLO mail-oi0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752803AbcFJKnr (ORCPT ); Fri, 10 Jun 2016 06:43:47 -0400 Reply-To: minyard@acm.org Subject: Re: [v2,02/10] i2c-i801: Move hostcfg set/reset to i801_access() References: <1464570544-975-3-git-send-email-minyard@acm.org> <20160609093945.GD24234@mail.corp.redhat.com> To: Benjamin Tissoires Cc: Jean Delvare , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Corey Minyard From: Corey Minyard Message-ID: <575A99DA.8080308@acm.org> Date: Fri, 10 Jun 2016 05:43:38 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: <20160609093945.GD24234@mail.corp.redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/09/2016 04:39 AM, Benjamin Tissoires wrote: > On May 29 2016 or thereabouts, Corey Minyard wrote: >> From: Corey Minyard >> >> The HSTCFG register save/restore was done in i2c_block_transaction, >> but all the checks were already done in i801_access, so move it into >> those checks. >> >> This results in a small savings of code, and moves some special >> handing for I2C transactions into code that is already handling >> special things for I2C transactions. >> >> Signed-off-by: Corey Minyard >> --- >> drivers/i2c/busses/i2c-i801.c | 41 +++++++++++++++++++---------------------- >> 1 file changed, 19 insertions(+), 22 deletions(-) >> >> diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c >> index 818c0c8..205f9d0 100644 >> --- a/drivers/i2c/busses/i2c-i801.c >> +++ b/drivers/i2c/busses/i2c-i801.c >> @@ -661,20 +661,6 @@ static int i801_block_transaction(struct i801_priv *priv, >> int command, int hwpec) >> { >> int result = 0; >> - unsigned char hostc; >> - >> - if (command == I2C_SMBUS_I2C_BLOCK_DATA) { >> - if (read_write == I2C_SMBUS_WRITE) { >> - /* set I2C_EN bit in configuration register */ >> - pci_read_config_byte(priv->pci_dev, SMBHSTCFG, &hostc); >> - pci_write_config_byte(priv->pci_dev, SMBHSTCFG, >> - hostc | SMBHSTCFG_I2C_EN); >> - } else if (!(priv->features & FEATURE_I2C_BLOCK_READ)) { >> - dev_err(&priv->pci_dev->dev, >> - "I2C block read is unsupported!\n"); >> - return -EOPNOTSUPP; >> - } >> - } >> >> if (read_write == I2C_SMBUS_WRITE >> || command == I2C_SMBUS_I2C_BLOCK_DATA) { >> @@ -699,11 +685,6 @@ static int i801_block_transaction(struct i801_priv *priv, >> read_write, >> command); >> >> - if (command == I2C_SMBUS_I2C_BLOCK_DATA >> - && read_write == I2C_SMBUS_WRITE) { >> - /* restore saved configuration register value */ >> - pci_write_config_byte(priv->pci_dev, SMBHSTCFG, hostc); >> - } >> return result; >> } >> >> @@ -715,6 +696,7 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr, >> int hwpec; >> int block = 0; >> int ret = 0, xact = 0; >> + int hostc = -1; >> struct i801_priv *priv = i2c_get_adapdata(adap); >> >> pm_runtime_get_sync(&priv->pci_dev->dev); >> @@ -764,12 +746,24 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr, >> /* NB: page 240 of ICH5 datasheet shows that the R/#W >> * bit should be cleared here, even when reading */ >> outb_p((addr & 0x7f) << 1, SMBHSTADD(priv)); >> - if (read_write == I2C_SMBUS_READ) { >> + if (read_write == I2C_SMBUS_WRITE) { >> + unsigned char thostc; >> + >> + outb_p(command, SMBHSTCMD(priv)); >> + /* set I2C_EN bit in configuration register */ >> + pci_read_config_byte(priv->pci_dev, SMBHSTCFG, &thostc); >> + pci_write_config_byte(priv->pci_dev, SMBHSTCFG, >> + thostc | SMBHSTCFG_I2C_EN); >> + hostc = thostc; >> + } else if (!(priv->features & FEATURE_I2C_BLOCK_READ)) { > nitpick: I'd prefer seeing: > if (write) { > foo > } else { > if (!FEATURE_I2C_BLOCK_READ) { > goto out > } > bar > } > > It's equivalent but I feel like it's easier to understand. First, thanks for all the reviews. I really appreciate it. On this particular change, it's moved from another location unchanged, and it follows the style of the rest of the file. I personally think it's better to leave it like it is. -corey > Other than that, no strong opinion on the patch itself, but it's correct > (the code path stays the same): > Reviewed-by: Benjamin Tissoires > > Cheers, > Benjamin > >> + dev_err(&priv->pci_dev->dev, >> + "I2C block read is unsupported!\n"); >> + ret = -EOPNOTSUPP; >> + goto out; >> + } else >> /* NB: page 240 of ICH5 datasheet also shows >> * that DATA1 is the cmd field when reading */ >> outb_p(command, SMBHSTDAT1(priv)); >> - } else >> - outb_p(command, SMBHSTCMD(priv)); >> block = 1; >> break; >> default: >> @@ -798,6 +792,9 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr, >> outb_p(inb_p(SMBAUXCTL(priv)) & >> ~(SMBAUXCTL_CRC | SMBAUXCTL_E32B), SMBAUXCTL(priv)); >> >> + if (hostc >= 0) >> + pci_write_config_byte(priv->pci_dev, SMBHSTCFG, hostc); >> + >> if (block) >> goto out; >> if (ret)