From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Date: Mon, 20 May 2013 13:26:41 +0000 Subject: Re: [lm-sensors] sensors-detect:: Drop detection of DS1621-like chips Message-Id: <20130520132641.GA32402@roeck-us.net> List-Id: References: <20130520141525.59931252@endymion.delvare> In-Reply-To: <20130520141525.59931252@endymion.delvare> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lm-sensors@vger.kernel.org On Mon, May 20, 2013 at 02:15:25PM +0200, Jean Delvare wrote: > Detection of the Dallas/Maxim DS1621, DS1625 and DS1631 chips is weak > and likely to result in false positives. There's no rationale for > keeping it in sensors-detect as these chips are not found in desktop > computer systems. So drop detection of these chips altogether. > --- Good idea. Guenter > prog/detect/sensors-detect | 46 --------------------------------------------- > 1 file changed, 46 deletions(-) > > --- lm-sensors.orig/prog/detect/sensors-detect 2013-05-20 13:25:33.992641174 +0200 > +++ lm-sensors/prog/detect/sensors-detect 2013-05-20 14:11:21.668063379 +0200 > @@ -803,11 +803,6 @@ use vars qw(@i2c_adapter_names); > i2c_addrs => [0x2c..0x2f], > i2c_detect => sub { adm9240_detect(@_, 0); }, > }, { > - name => "Dallas Semiconductor DS1621/DS1631", > - driver => "ds1621", > - i2c_addrs => [0x48..0x4f], > - i2c_detect => sub { ds1621_detect(@_); }, > - }, { > name => "Dallas Semiconductor DS1780", > driver => "adm9240", > i2c_addrs => [0x2c..0x2f], > @@ -4357,47 +4352,6 @@ sub lm92_detect > return ($chip = 0) ? 4 : 2; > } > > -# Registers used: > -# 0xAA: Temperature > -# 0xA1: High limit > -# 0xA2: Low limit > -# 0xA8: Counter > -# 0xA9: Slope > -# 0xAC: Configuration > -# Detection is weak. We check if bit 4 (NVB) is clear, because it is > -# unlikely to be set (would mean that EEPROM is currently being accessed). > -# We also check the value of the counter and slope registers, the datasheet > -# doesn't mention the possible values but the conversion formula together > -# with experimental evidence suggest possible sanity checks. > -# Not all devices enjoy SMBus read word transactions, so we do as much as > -# possible with read byte transactions first, and only use read word > -# transactions second. > -sub ds1621_detect > -{ > - my ($file, $addr) = @_; > - > - my $conf = i2c_smbus_read_byte_data($file, 0xAC); > - return if ($conf & 0x10); > - > - my $temp = i2c_smbus_read_word_data($file, 0xAA); > - return if $temp < 0 || ($temp & 0x0f00); > - # On the DS1631, the following two checks are too strict in theory, > - # but in practice I very much doubt that anyone will set temperature > - # limits not a multiple of 0.5 degrees C. > - my $high = i2c_smbus_read_word_data($file, 0xA1); > - return if $high < 0 || ($high & 0x7f00); > - my $low = i2c_smbus_read_word_data($file, 0xA2); > - return if $low < 0 || ($low & 0x7f00); > - > - return if ($temp = 0 && $high = 0 && $low = 0 && $conf = 0); > - > - # Old versions of the DS1621 apparently don't have the counter and > - # slope registers (or they return crap) > - my $counter = i2c_smbus_read_byte_data($file, 0xA8); > - my $slope = i2c_smbus_read_byte_data($file, 0xA9); > - return ($slope = 0x10 && $counter <= $slope) ? 3 : 2; > -} > - > # Chip to detect: 0 = LM80, 1 = LM96080 > # Registers used: > # 0x00: Configuration register > > > -- > Jean Delvare > _______________________________________________ lm-sensors mailing list lm-sensors@lm-sensors.org http://lists.lm-sensors.org/mailman/listinfo/lm-sensors