Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933402Ab3GOQ5n (ORCPT ); Mon, 15 Jul 2013 12:57:43 -0400 Received: from zoneX.GCU-Squad.org ([194.213.125.0]:45358 "EHLO services.gcu-squad.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932297Ab3GOQ5l (ORCPT ); Mon, 15 Jul 2013 12:57:41 -0400 Date: Mon, 15 Jul 2013 18:57:27 +0200 From: Jean Delvare To: Wei Ni , Guenter Roeck Cc: , , , Subject: Re: [PATCH v3 2/4] hwmon: (lm90) use macro defines for the status bit Message-ID: <20130715185727.4ebde8c4@endymion.delvare> In-Reply-To: <1373615287-18502-3-git-send-email-wni@nvidia.com> References: <1373615287-18502-1-git-send-email-wni@nvidia.com> <1373615287-18502-3-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: 6222 Lines: 161 Hi Wei, Guenter, On Fri, 12 Jul 2013 15:48:05 +0800, Wei Ni wrote: > Add bit defines for the status register. Regarding the subject: for me these are constants, not macros. AFAIK the term "macro" refers to defines with parameters only. > Signed-off-by: Wei Ni > --- > drivers/hwmon/lm90.c | 72 ++++++++++++++++++++++++++++++++++---------------- > 1 file changed, 49 insertions(+), 23 deletions(-) > > diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c > index 5f30f90..c90037f 100644 > --- a/drivers/hwmon/lm90.c > +++ b/drivers/hwmon/lm90.c > @@ -179,6 +179,19 @@ enum chips { lm90, adm1032, lm99, lm86, max6657, max6659, adt7461, max6680, > #define LM90_HAVE_TEMP3 (1 << 6) /* 3rd temperature sensor */ > #define LM90_HAVE_BROKEN_ALERT (1 << 7) /* Broken alert */ > > +/* LM90 status */ > +#define LM90_STATUS_LTHRM (1 << 0) /* local THERM limit tripped */ > +#define LM90_STATUS_RTHRM (1 << 1) /* remote THERM limit tripped */ > +#define LM90_STATUS_OPEN (1 << 2) /* remote is an open circuit */ > +#define LM90_STATUS_RLOW (1 << 3) /* remote low temp limit tripped */ > +#define LM90_STATUS_RHIGH (1 << 4) /* remote high temp limit tripped */ > +#define LM90_STATUS_LLOW (1 << 5) /* local low temp limit tripped */ > +#define LM90_STATUS_LHIGH (1 << 6) /* local high temp limit tripped */ > +#define LM90_STATUS_BUSY (1 << 7) /* ADC is converting */ LM90_STATUS_BUSY is never used anywhere so please don't define it. > + > +#define MAX6696_STATUS2_RLOW (1 << 3) /* remote2 low temp limit tripped */ > +#define MAX6696_STATUS2_RHIGH (1 << 4) /* remote2 high temp limit tripped */ > + > /* > * Driver data (common to all clients) > */ > @@ -1417,6 +1430,36 @@ static void lm90_init_client(struct i2c_client *client) > i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1, config); > } > > +static bool lm90_is_tripped(struct i2c_client *client) > +{ > + struct lm90_data *data = i2c_get_clientdata(client); > + u8 status, status2 = 0; > + > + lm90_read_reg(client, LM90_REG_R_STATUS, &status); > + > + if (data->kind == max6696) > + lm90_read_reg(client, MAX6696_REG_R_STATUS2, &status2); > + > + if ((status & 0x7f) == 0 && (status2 & 0xfe) == 0) > + return false; It's a bit disappointing to not use the freshly introduced constants. That being said I agree it would make the code hard to read, so you can leave it as is. Unrelated to this patch, but Guenter, I am worried about the MAX6696 handling here. I realize that I am the one who accepted your code, but now it looks wrong. Specifically: * We check for (status2 & 0xfe) i.e. 7 alarm bits, but the code below only reports 2 alarms bits. So if any of the 5 other alarm bits in STATUS2 are, we may return true (chip is tripped) but not print the cause. * At least bits 1 and 2 of STATUS 2 fit totally fine in the driver as it currently exists, so I can't think of any reason for not handling them. Why are we not? Ideally we should print a message for every alarm bit so that we never return "true" without printing a message. Even though OT2 limits aren't handled by the driver... * If you think this piece of code shouldn't deal with OT/THERM limits because they do not trigger an SMBus alarm, this can be discussed, but all chips should be handled the same in this respect then. * Why in the first place is max6696's data->alert_alarms set to 0x187c and not 0x1c7c? Including 1OPEN but not 2OPEN makes no sense. > + > + if (status & (LM90_STATUS_LLOW | LM90_STATUS_LHIGH | LM90_STATUS_LTHRM)) > + dev_warn(&client->dev, > + "temp%d out of range, please check!\n", 1); > + if (status & (LM90_STATUS_RLOW | LM90_STATUS_RHIGH | LM90_STATUS_RTHRM)) > + dev_warn(&client->dev, > + "temp%d out of range, please check!\n", 2); > + if (status & LM90_STATUS_OPEN) > + dev_warn(&client->dev, > + "temp%d diode open, please check!\n", 2); > + > + if (status2 & (MAX6696_STATUS2_RLOW | MAX6696_STATUS2_RHIGH)) > + dev_warn(&client->dev, > + "temp%d out of range, please check!\n", 3); > + > + return true; > +} > + > static int lm90_probe(struct i2c_client *client, > const struct i2c_device_id *id) > { > @@ -1515,36 +1558,19 @@ static int lm90_remove(struct i2c_client *client) > > static void lm90_alert(struct i2c_client *client, unsigned int flag) > { > - struct lm90_data *data = i2c_get_clientdata(client); > - u8 config, alarms, alarms2 = 0; > - > - lm90_read_reg(client, LM90_REG_R_STATUS, &alarms); > - > - if (data->kind == max6696) > - lm90_read_reg(client, MAX6696_REG_R_STATUS2, &alarms2); > - > - if ((alarms & 0x7f) == 0 && (alarms2 & 0xfe) == 0) { > + if (!lm90_is_tripped(client)) { You could swap the success and failure cases to avoid this negation. > dev_info(&client->dev, "Everything OK\n"); > } else { > - if (alarms & 0x61) > - dev_warn(&client->dev, > - "temp%d out of range, please check!\n", 1); > - if (alarms & 0x1a) > - dev_warn(&client->dev, > - "temp%d out of range, please check!\n", 2); > - if (alarms & 0x04) > - dev_warn(&client->dev, > - "temp%d diode open, please check!\n", 2); > - > - if (alarms2 & 0x18) > - dev_warn(&client->dev, > - "temp%d out of range, please check!\n", 3); > - > /* > * Disable ALERT# output, because these chips don't implement > * SMBus alert correctly; they should only hold the alert line > * low briefly. > */ > + struct lm90_data *data = i2c_get_clientdata(client); > + u8 config, alarms; > + > + lm90_read_reg(client, LM90_REG_R_STATUS, &alarms); You end up reading LM90_REG_R_STATUS, which is not OK. This register contains self-clearing bits, so there is no guarantee that the second read will return the same value as the first read. You'll have to come up with a different approach that reads LM90_REG_R_STATUS only once. > + > if ((data->flags & LM90_HAVE_BROKEN_ALERT) > && (alarms & data->alert_alarms)) { > dev_dbg(&client->dev, "Disabling ALERT#\n"); -- 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/