w1_therm: Retries: remove old code add CRC

w1_therm includes some obsolete code to detect bad_roms, this is no
longer relevant.
The retry code is only used for this bad_rom test, however there is a
CRC check that detects a bad read, but does not trigger a retry. This
patch removes all the bad_rom code and uses the CRC check to trigger
retries.

Signed-off-by: David Stevenson <david@avoncliff.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
David Stevenson 2012-12-18 01:37:56 +00:00 committed by Greg Kroah-Hartman
parent e5279ff6c9
commit 867ff9880d

View file

@ -45,10 +45,6 @@ MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature famil
static int w1_strong_pullup = 1;
module_param_named(strong_pullup, w1_strong_pullup, int, 0);
static u8 bad_roms[][9] = {
{0xaa, 0x00, 0x4b, 0x46, 0xff, 0xff, 0x0c, 0x10, 0x87},
{}
};
static ssize_t w1_therm_read(struct device *device,
struct device_attribute *attr, char *buf);
@ -168,16 +164,6 @@ static inline int w1_convert_temp(u8 rom[9], u8 fid)
return 0;
}
static int w1_therm_check_rom(u8 rom[9])
{
int i;
for (i=0; i<sizeof(bad_roms)/9; ++i)
if (!memcmp(bad_roms[i], rom, 9))
return 1;
return 0;
}
static ssize_t w1_therm_read(struct device *device,
struct device_attribute *attr, char *buf)
@ -194,10 +180,11 @@ static ssize_t w1_therm_read(struct device *device,
memset(rom, 0, sizeof(rom));
verdict = 0;
crc = 0;
while (max_trying--) {
verdict = 0;
crc = 0;
if (!w1_reset_select_slave(sl)) {
int count = 0;
unsigned int tm = 750;
@ -249,7 +236,7 @@ static ssize_t w1_therm_read(struct device *device,
}
}
if (!w1_therm_check_rom(rom))
if (verdict)
break;
}
@ -260,7 +247,7 @@ static ssize_t w1_therm_read(struct device *device,
if (verdict)
memcpy(sl->rom, rom, sizeof(sl->rom));
else
dev_warn(device, "18S20 doesn't respond to CONVERT_TEMP.\n");
dev_warn(device, "Read failed CRC check\n");
for (i = 0; i < 9; ++i)
c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", sl->rom[i]);