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authorDavid Stevenson <david@avoncliff.com>2012-12-18 01:37:56 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-01-15 23:43:05 -0800
commit867ff9880d5d71a38433c0471bc09bcc10851f36 (patch)
treebc723c92a38a39d5bdb27584ebdb069d297322f3 /drivers/w1
parente5279ff6c9f5e950feac6e6f48621db912324c07 (diff)
downloadlinux-867ff9880d5d71a38433c0471bc09bcc10851f36.tar.gz
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>
Diffstat (limited to 'drivers/w1')
-rw-r--r--drivers/w1/slaves/w1_therm.c25
1 files changed, 6 insertions, 19 deletions
diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c
index 92d08e7fcba..5ef583d520f 100644
--- a/drivers/w1/slaves/w1_therm.c
+++ b/drivers/w1/slaves/w1_therm.c
@@ -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]);