David Fries 80c002ddd2 W1: w1_therm.c is flagging 0C etc as invalid ... 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>		2008-01-22 09:17:48 -08:00
..
masters	W1: fix memset size error	2007-11-14 18:45:36 -08:00
slaves	W1: w1_therm.c is flagging 0C etc as invalid	2008-01-22 09:17:48 -08:00
Kconfig	Kbuild/doc: fix links to Documentation files	2007-10-30 14:26:30 -07:00
Makefile
w1_family.c
w1_family.h
w1_int.c	w1: fix w1_remove_master_device() searching	2007-08-22 19:52:46 -07:00
w1_int.h
w1_io.c
w1_log.h
w1_netlink.c
w1_netlink.h
w1.c	w1: decrement slave counter only in ->release() callback	2008-01-14 08:52:22 -08:00
w1.h