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path: root/drivers/w1/slaves/w1_therm.c
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2009-02-11w1: w1 temp calculation overflow fixIan Dall
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=12646 When the temperature exceeds 32767 milli-degrees the temperature overflows to -32768 millidegrees. These are bothe well within the -55 - +125 degree range for the sensor. Fix overflow in left-shift of a u8. Signed-off-by: Ian Dall <ian@beware.dropbear.id.au> Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16W1: w1_therm consistent mutex access code cleanupDavid Fries
sl->master->mutex and dev->mutex refer to the same mutex variable, but be consistent and use the same set of pointers for the lock and unlock calls. It is less confusing (and one less pointer dereference this way). Signed-off-by: David Fries <david@fries.net> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16W1: w1_therm fix user buffer overflow and catDavid Fries
Fixed data reading bug by replacing binary attribute with device one. Switching the sysfs read from bin_attribute to device_attribute. The data is far under PAGE_SIZE so the binary interface isn't required. As the device_attribute interface will make one call to w1_therm_read per file open and buffer, the result is, the following problems go away. buffer overflow: Execute a short read on w1_slave and w1_therm_read_bin would still return the full string size worth of data clobbering the user space buffer when it returned. Switching to device_attribute avoids the buffer overflow problems. With the snprintf formatted output dealing with short reads without doing a conversion per read would have been difficult. bad behavior: `cat w1_slave` would cause two temperature conversions to take place. Previously the code assumed W1_SLAVE_DATA_SIZE would be returned with each read. It would not return 0 unless the offset was less than W1_SLAVE_DATA_SIZE. The result was the first read did a temperature conversion, filled the buffer and returned, the offset in the second read would be less than W1_SLAVE_DATA_SIZE and also fill the buffer and return, the third read would finnally have a big enough offset to return 0 and cause cat to stop. Now w1_therm_read will be called at most once per open. Signed-off-by: David Fries <david@fries.net> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16W1: feature, w1_therm.c use strong pullup and documentationDavid Fries
Added strong pullup to thermal sensor driver and general documentation on the sensor. Signed-off-by: David Fries <david@fries.net> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06W1: w1_therm.c standardize units to millidegrees CDavid Fries
Standardize the temperature units to millidegrees C for the two sensor conversion routines. Previously the routines were, w1_DS18B20_convert_temp degrees C w1_DS18S20_convert_temp millidegrees C Unfortunately this will break any program using the ds18b20 value as it will now be 1000 times bigger. Fortunately there can't be that many users out there, or some of these bugs will have been fixed by now, such as the negative C error (see previous patch) that makes me think the ds18b20 is the better choice to change because of the current bugs. Signed-off-by: David Fries <david@fries.net> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-22W1: w1_therm.c is flagging 0C etc as invalidDavid Fries
The extra rom[0] check is flagging valid temperatures as invalid when there is already a CRC data transmission check. w1_therm_read_bin() if (rom[8] == crc && rom[0]) verdict = 1; Requiring rom[0] to be non-zero will flag as invalid temperature conversions when the low byte is zero, specifically the temperatures 0C, 16C, 32C, 48C, -16C, -32C, and -48C. The CRC check is produced on the device for the previous 8 bytes and is required to ensure the data integrity in transmission. I don't see why the extra check for rom[0] being non-zero is in there. Evgeniy Polyakov didn't know either. Just for a check I unplugged the sensor, executed a temperature conversion, and read the results. The read was all ff's, which also failed the CRC, so it doesn't need to protect against a disconnected sensor. I have more extensive patches in the work, but these two trivial ones will do for today. I would like to hear from people who use the ds2490 USB to one wire dongle. 1 if you would be willing to test the patches as I currently only have the one sensor on a short parisite powered wire, 2 if there is any cheap sources for the ds2490. Signed-off-by: David Fries <david@fries.net> Acked-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-22W1: w1_therm.c ds18b20 decode freezing temperatures correctlyDavid Fries
Correct the decoding of negative C temperatures. The code did a binary OR of two bytes to make a 16 bit value, but assignd it to an integer. This caused the value to not be sign extended and to loose that it was a negative number in the assignment. Before the patch (in my freezer), w1_slave ed fe 4b 46 7f ff 03 10 e4 : crc=e4 YES ed fe 4b 46 7f ff 03 10 e4 t=4078 With the patch, e3 fe 4b 46 7f ff 0d 10 81 : crc=81 YES e3 fe 4b 46 7f ff 0d 10 81 t=-17 Signed-off-by: David Fries <david@fries.net> Acked-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-11sysfs: add parameter "struct bin_attribute *" in .read/.write methods for ↵Zhang Rui
sysfs binary attributes Well, first of all, I don't want to change so many files either. What I do: Adding a new parameter "struct bin_attribute *" in the .read/.write methods for the sysfs binary attributes. In fact, only the four lines change in fs/sysfs/bin.c and include/linux/sysfs.h do the real work. But I have to update all the files that use binary attributes to make them compatible with the new .read and .write methods. I'm not sure if I missed any. :( Why I do this: For a sysfs attribute, we can get a pointer pointing to the struct attribute in the .show/.store method, while we can't do this for the binary attributes. I don't know why this is different, but this does make it not so handy to use the binary attributes as the regular ones. So I think this patch is reasonable. :) Who benefits from it: The patch that exposes ACPI tables in sysfs requires such an improvement. All the table binary attributes share the same .read method. Parameter "struct bin_attribute *" is used to get the table signature and instance number which are used to distinguish different ACPI table binary attributes. Without this parameter, we need to offer different .read methods for different ACPI table binary attributes. This is impossible as there are various ACPI tables on different platforms, and we don't know what they are until they are loaded. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-11sysfs: kill unnecessary attribute->ownerTejun Heo
sysfs is now completely out of driver/module lifetime game. After deletion, a sysfs node doesn't access anything outside sysfs proper, so there's no reason to hold onto the attribute owners. Note that often the wrong modules were accounted for as owners leading to accessing removed modules. This patch kills now unnecessary attribute->owner. Note that with this change, userland holding a sysfs node does not prevent the backing module from being unloaded. For more info regarding lifetime rule cleanup, please read the following message. http://article.gmane.org/gmane.linux.kernel/510293 (tweaked by Greg to not delete the field just yet, to make it easier to merge things properly.) Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-06-28w1_therm_read_bin: don't call flush_signals()Evgeniy Polyakov
This can disrupt userspace signal management. Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Cc: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12[PATCH] w1: Use ARRAY_SIZE macro when appropriateAhmed S. Darwish
A patch to use ARRAY_SIZE macro already defined in kernel.h Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com> Acked-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-04[PATCH] severing module.h->sched.hAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-06-22[PATCH] w1: Use mutexes instead of semaphores.Evgeniy Polyakov
Use mutexes instead of semaphores. Patch tested on x86_64 and i386 with test bus master driver. Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-22[PATCH] w1: Userspace communication protocol over connector.Evgeniy Polyakov
There are three types of messages between w1 core and userspace: 1. Events. They are generated each time new master or slave device found either due to automatic or requested search. 2. Userspace commands. Includes read/write and search/alarm search comamnds. 3. Replies to userspace commands. From: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-03-23[PATCH] W1: Move w1 bus master code into 'w1/masters' and move w1 slave code ↵Evgeniy Polyakov
into 'w1/slaves' Signed-off-by: Ben Gardner <bgardner@wabtec.com> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>