Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751377Ab3IPT3X (ORCPT ); Mon, 16 Sep 2013 15:29:23 -0400 Received: from zoneX.GCU-Squad.org ([194.213.125.0]:30925 "EHLO services.gcu-squad.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750982Ab3IPT3W (ORCPT ); Mon, 16 Sep 2013 15:29:22 -0400 Date: Mon, 16 Sep 2013 21:29:08 +0200 From: Jean Delvare To: Wei Ni Cc: , , , Subject: Re: [PATCH RESEND v4] hwmon: (lm90) split set&show temp as common codes Message-ID: <20130916212908.25248fae@endymion.delvare> In-Reply-To: <1375785417-13650-1-git-send-email-wni@nvidia.com> References: <1375785417-13650-1-git-send-email-wni@nvidia.com> X-Mailer: Claws Mail 3.9.0 (GTK+ 2.24.18; x86_64-suse-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9586 Lines: 303 Hi Wei, On Tue, 6 Aug 2013 18:36:57 +0800, Wei Ni wrote: > Split set&show temp codes as common functions, so we can use it > directly when implement linux thermal framework. > And handle error return value for the lm90_select_remote_channel > and write_tempx, then set_temp8 and set_temp11 could return it > to user-space. > > Signed-off-by: Wei Ni > --- > drivers/hwmon/lm90.c | 150 +++++++++++++++++++++++++++++++++----------------- > 1 file changed, 99 insertions(+), 51 deletions(-) > > diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c > index cdff742..6de8e01 100644 > --- a/drivers/hwmon/lm90.c > +++ b/drivers/hwmon/lm90.c > @@ -422,20 +422,29 @@ static int lm90_read16(struct i2c_client *client, u8 regh, u8 regl, u16 *value) > * various registers have different meanings as a result of selecting a > * non-default remote channel. > */ > -static inline void lm90_select_remote_channel(struct i2c_client *client, > +static inline int lm90_select_remote_channel(struct i2c_client *client, > struct lm90_data *data, > int channel) > { > u8 config; > + int err = 0; You don't have to initialize err, as you return immediately when an error happens. You can just... > > if (data->kind == max6696) { > lm90_read_reg(client, LM90_REG_R_CONFIG1, &config); > config &= ~0x08; > if (channel) > config |= 0x08; > - i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1, > - config); > + err = i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1, > + config); > + if (err < 0) { > + dev_err(&client->dev, > + "Failed to select remote channel %d, err %d\n", > + channel, err); > + return err; > + } > } > + > + return err; ... return 0 here. > } > > /* > @@ -702,29 +711,34 @@ static u16 temp_to_u16_adt7461(struct lm90_data *data, long val) > * Sysfs stuff > */ > > -static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr, > - char *buf) > +static int read_temp8(struct device *dev, int index) > { > - struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); > struct lm90_data *data = lm90_update_device(dev); > int temp; > > if (data->kind == adt7461) > - temp = temp_from_u8_adt7461(data, data->temp8[attr->index]); > + temp = temp_from_u8_adt7461(data, data->temp8[index]); > else if (data->kind == max6646) > - temp = temp_from_u8(data->temp8[attr->index]); > + temp = temp_from_u8(data->temp8[index]); > else > - temp = temp_from_s8(data->temp8[attr->index]); > + temp = temp_from_s8(data->temp8[index]); > > /* +16 degrees offset for temp2 for the LM99 */ > - if (data->kind == lm99 && attr->index == 3) > + if (data->kind == lm99 && index == 3) > temp += 16000; > > - return sprintf(buf, "%d\n", temp); > + return temp; > } > > -static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr, > - const char *buf, size_t count) > +static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr, > + char *buf) > +{ > + struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); > + > + return sprintf(buf, "%d\n", read_temp8(dev, attr->index)); > +} > + > +static int write_temp8(struct device *dev, int index, long val) > { > static const u8 reg[8] = { > LM90_REG_W_LOCAL_LOW, > @@ -737,60 +751,79 @@ static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr, > MAX6659_REG_W_REMOTE_EMERG, > }; > > - struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); > struct i2c_client *client = to_i2c_client(dev); > struct lm90_data *data = i2c_get_clientdata(client); > - int nr = attr->index; > - long val; > int err; > > - err = kstrtol(buf, 10, &val); > - if (err < 0) > - return err; > - > /* +16 degrees offset for temp2 for the LM99 */ > - if (data->kind == lm99 && attr->index == 3) > + if (data->kind == lm99 && index == 3) > val -= 16000; > > mutex_lock(&data->update_lock); > if (data->kind == adt7461) > - data->temp8[nr] = temp_to_u8_adt7461(data, val); > + data->temp8[index] = temp_to_u8_adt7461(data, val); > else if (data->kind == max6646) > - data->temp8[nr] = temp_to_u8(val); > + data->temp8[index] = temp_to_u8(val); > else > - data->temp8[nr] = temp_to_s8(val); > - > - lm90_select_remote_channel(client, data, nr >= 6); > - i2c_smbus_write_byte_data(client, reg[nr], data->temp8[nr]); > - lm90_select_remote_channel(client, data, 0); > + data->temp8[index] = temp_to_s8(val); > > + err = lm90_select_remote_channel(client, data, index >= 6); > + err |= i2c_smbus_write_byte_data(client, reg[index], data->temp8[index]); > + err |= lm90_select_remote_channel(client, data, 0); You can't use |= for error codes. Imagine that lm90_select_remote_channel() returns -EIO (-5) and i2c_smbus_write_byte_data() returns -EAGAIN (-11), err will have value -EPERM (-1) which makes no sense. You have to report errors as soon as they happen so that the error code isn't lost. What you can do is: if ((err = f1(...)) || (err = f2(...)) || (err = f3(...))) { dev_err(...); return err; } I think checkpatch will complain about that construct but me, I'm fine with it. > + if (err) > + dev_err(dev, "write_temp8 failed!\n"); > mutex_unlock(&data->update_lock); > + > + return err; > +} > + > +static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr, > + const char *buf, size_t count) > +{ > + struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); > + int index = attr->index; > + long val; > + int err; > + > + err = kstrtol(buf, 10, &val); > + if (err < 0) > + return err; > + > + err = write_temp8(dev, index, val); > + if (err < 0) > + return err; > + > return count; > } > > -static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr, > - char *buf) > +static int read_temp11(struct device *dev, int index) > { > - struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr); > struct lm90_data *data = lm90_update_device(dev); > int temp; > > if (data->kind == adt7461) > - temp = temp_from_u16_adt7461(data, data->temp11[attr->index]); > + temp = temp_from_u16_adt7461(data, data->temp11[index]); > else if (data->kind == max6646) > - temp = temp_from_u16(data->temp11[attr->index]); > + temp = temp_from_u16(data->temp11[index]); > else > - temp = temp_from_s16(data->temp11[attr->index]); > + temp = temp_from_s16(data->temp11[index]); > > /* +16 degrees offset for temp2 for the LM99 */ > - if (data->kind == lm99 && attr->index <= 2) > + if (data->kind == lm99 && index <= 2) > temp += 16000; > > - return sprintf(buf, "%d\n", temp); > + return temp; > } > > -static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr, > - const char *buf, size_t count) > +static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr, > + char *buf) > +{ > + struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr); > + > + return sprintf(buf, "%d\n", read_temp11(dev, attr->index)); > +} > + > +static int write_temp11(struct device *dev, int nr, int index, long val) > { > struct { > u8 high; > @@ -804,18 +837,10 @@ static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr, > { LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL, 1 } > }; > > - struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr); > struct i2c_client *client = to_i2c_client(dev); > struct lm90_data *data = i2c_get_clientdata(client); > - int nr = attr->nr; > - int index = attr->index; > - long val; > int err; > > - err = kstrtol(buf, 10, &val); > - if (err < 0) > - return err; > - > /* +16 degrees offset for temp2 for the LM99 */ > if (data->kind == lm99 && index <= 2) > val -= 16000; > @@ -830,15 +855,38 @@ static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr, > else > data->temp11[index] = temp_to_s8(val) << 8; > > - lm90_select_remote_channel(client, data, reg[nr].channel); > - i2c_smbus_write_byte_data(client, reg[nr].high, > + err = lm90_select_remote_channel(client, data, reg[nr].channel); > + err |= i2c_smbus_write_byte_data(client, reg[nr].high, > data->temp11[index] >> 8); > if (data->flags & LM90_HAVE_REM_LIMIT_EXT) > - i2c_smbus_write_byte_data(client, reg[nr].low, > - data->temp11[index] & 0xff); > - lm90_select_remote_channel(client, data, 0); > + err |= i2c_smbus_write_byte_data(client, reg[nr].low, > + data->temp11[index] & 0xff); > + err |= lm90_select_remote_channel(client, data, 0); > + if (err) > + dev_err(dev, "write_temp11 failed !\n"); Same here, you can't use |=. Also, no space needed before exclamation marks in English. > > mutex_unlock(&data->update_lock); > + > + return err; > +} > + > +static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr, > + const char *buf, size_t count) > +{ > + struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr); > + int nr = attr->nr; > + int index = attr->index; > + long val; > + int err; > + > + err = kstrtol(buf, 10, &val); > + if (err < 0) > + return err; > + > + err = write_temp11(dev, nr, index, val); > + if (err < 0) > + return err; > + > return count; > } > -- Jean Delvare -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/