From 70de907670a2ed978e207e3a9b6a2da202256351 Mon Sep 17 00:00:00 2001
From: Jean Delvare <khali@linux-fr.org>
Date: Wed, 4 Feb 2009 09:58:07 +0000
Subject: [PATCH] Do not include in the driver list the PCI and USB drivers
 which are autoloaded by the system. Excluding them avoids unnecessary
 attempts to load already loaded drivers and also helps with device numbering
 stability (#2368).

git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@5635 7894878c-1315-0410-8ee3-d5d059ff63e0
---
 CHANGES                    |  1 +
 prog/detect/sensors-detect | 88 ++++++++++++++++++++++++++++++--------
 2 files changed, 71 insertions(+), 18 deletions(-)

diff --git a/CHANGES b/CHANGES
index 4c248eb7..9fc76d2f 100644
--- a/CHANGES
+++ b/CHANGES
@@ -67,6 +67,7 @@ SVN-HEAD
                   Print warnings about missing modules on screen
                   Fix detection of older DS1621
                   Add nNidia nForce MCP67, MCP73, MCP79 SMBus support
+                  Exclude auto-loaded PCI and USB drivers from list (#2368)
   sensors-detect-stat.pl: Delete (functionality merged into sensors-detect)
   sysconfig-lm_sensors-convert: Sample config file conversion script (#2246)
 
diff --git a/prog/detect/sensors-detect b/prog/detect/sensors-detect
index 2b31765f..6f82b6b5 100755
--- a/prog/detect/sensors-detect
+++ b/prog/detect/sensors-detect
@@ -2043,9 +2043,37 @@ sub initialize_cpu_list
 
 # @i2c_adapters is a list of references to hashes, one hash per I2C/SMBus
 # adapter present on the system. Each entry has the following keys: name
-# (directly taken from /sys/class/i2c-adapter) and driver.
+# (directly taken from /sys/class/i2c-adapter), driver and autoload.
 use vars qw(@i2c_adapters);
 
+# Find out whether the driver would be automatically loaded by the modalias
+# mechanism.
+sub classdev_driver_autoloads
+{
+	my $classdev = shift;
+	
+	my $modalias = sysfs_device_attribute("$classdev/device", "modalias");
+	if (!defined($modalias)) {
+		my $dev_link = readlink("$classdev/device");
+		if ($dev_link) {
+			$dev_link =~ s/\/[^\/]*$//;
+			$modalias = sysfs_device_attribute("$classdev/$dev_link",
+							   "modalias");
+		}
+	}
+	return 0 unless defined($modalias);
+
+	# At the moment we only handle PCI and USB drivers. Other driver
+	# types, most notably platform and i2c drivers, do not follow the
+	# device driver model to the letter, and often create their own
+	# devices. Such drivers appear to be autoloaded when they are not.
+	return 0 unless $modalias =~ m/^(pci|usb):/;
+
+	my $result = `modprobe -n -v --first-time $modalias 2>&1`;
+	return ($result =~ m/^insmod/ ||
+		$result =~ m/\balready in kernel\b/);
+}
+
 sub initialize_i2c_adapters_list
 {
 	my $entry;
@@ -2069,11 +2097,44 @@ sub initialize_i2c_adapters_list
 		$entry->{driver} = sysfs_device_driver("${class_dir}/i2c-$1/device")
 				|| find_i2c_adapter_driver($entry->{name})
 				|| 'UNKNOWN';
+
+		$entry->{autoload} = classdev_driver_autoloads("${class_dir}/i2c-$1");
 		$i2c_adapters[$1] = $entry;
 	}
 	closedir(ADAPTERS);
 }
 
+# %hwmon_autoloaded is a list of hwmon drivers which are autoloaded
+# (typically by udev.) We don't need to load these drivers ourselves.
+use vars qw(%hwmon_autoloaded);
+
+sub initialize_hwmon_autoloaded
+{
+	my $class_dir = "${sysfs_root}/class/hwmon";
+	opendir(local *HWMON, $class_dir) or return;
+
+	my ($hwmon, $driver);
+	while (defined($hwmon = readdir(HWMON))) {
+		next unless $hwmon =~ m/^hwmon\d+$/;
+
+		$driver = sysfs_device_driver("${class_dir}/$hwmon/device");
+		next unless defined($driver);
+
+		if (classdev_driver_autoloads("${class_dir}/$hwmon")) {
+			$driver =~ tr/-/_/;
+			$hwmon_autoloaded{$driver}++
+		}
+	}
+	closedir(HWMON);
+}
+
+sub hwmon_is_autoloaded
+{
+	my $driver = shift;
+	$driver =~ tr/-/_/;
+	return exists($hwmon_autoloaded{$driver});
+}
+
 ###########
 # MODULES #
 ###########
@@ -2119,20 +2180,6 @@ sub load_module
 	$modules_list{$normalized} = 1;
 }
 
-sub loaded_by_us
-{
-	my $sought = shift;
-	local $_;
-
-	$sought =~ tr/-/_/;
-	foreach (@modules_we_loaded) {
-		my $module = $_;
-		$module =~ tr/-/_/;
-		return 1 if $module eq $sought;
-	}
-	return 0;
-}
-
 sub initialize_modules_supported
 {
 	foreach my $chip (@chip_ids) {
@@ -5118,7 +5165,8 @@ sub generate_modprobes
 	# the adapter drivers so that the numbers will be the same. If not, then
 	# we only load the adapter drivers which are useful.
 	foreach $adap (@i2c_adapters) {
-		next unless loaded_by_us($adap->{driver});
+		next if $adap->{autoload};
+		next if $adap->{driver} eq 'UNKNOWN';
 		next if not defined $configfile and not $adap->{used};
 		$bus_modules{$adap->{driver}}++;
 	}
@@ -5148,7 +5196,8 @@ sub generate_modprobes
 				      "Otherwise, check http://www.lm-sensors.org/wiki/Devices for\n".
 				      "driver availability.\n\n";
 			} else {
-				$hwmon_modules{$driver}++;
+				$hwmon_modules{$driver}++
+					unless hwmon_is_autoloaded($driver);
 			}
 		}
 	}
@@ -5405,10 +5454,13 @@ sub main
 	      "Just press ENTER to continue: ";
 	<STDIN>;
 
+	initialize_hwmon_autoloaded();
 	foreach my $driver (keys %chips_detected) {
 		next unless @{$chips_detected{$driver}};
 		find_aliases($chips_detected{$driver});
-		print "\nDriver `$driver':\n";
+		print "\nDriver `$driver'";
+		print " (autoloaded)" if hwmon_is_autoloaded($driver);
+		print ":\n";
 		print_chips_report($chips_detected{$driver});
 	}
 	print "\n";