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.
Patch is against Raspberry 3.2.27 ( my test hardware) but has also been
tested against 3.7.
David Stevenson david at avoncliff.com
diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c
index 016dd7d..8166075 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);
@@ -159,16 +155,6 @@ 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)
@@ -183,10 +169,11 @@ 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;
@@ -214,7 +201,7 @@ static ssize_t w1_therm_read(struct device *device,
}
}
- if (!w1_therm_check_rom(rom))
+ if (verdict)
break;
}
--
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