From: Guenter Roeck Date: Thu, 6 Jan 2022 19:48:52 +0000 (-0800) Subject: hwmon: (lm90) Reduce maximum conversion rate for G781 X-Git-Tag: v4.19.228~56 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e3e20f10c234a73e4423ae29b45c2e13c7802657;p=thirdparty%2Fkernel%2Fstable.git hwmon: (lm90) Reduce maximum conversion rate for G781 [ Upstream commit a66c5ed539277b9f2363bbace0dba88b85b36c26 ] According to its datasheet, G781 supports a maximum conversion rate value of 8 (62.5 ms). However, chips labeled G781 and G780 were found to only support a maximum conversion rate value of 7 (125 ms). On the other side, chips labeled G781-1 and G784 were found to support a conversion rate value of 8. There is no known means to distinguish G780 from G781 or G784; all chips report the same manufacturer ID and chip revision. Setting the conversion rate register value to 8 on chips not supporting it causes unexpected behavior since the real conversion rate is set to 0 (16 seconds) if a value of 8 is written into the conversion rate register. Limit the conversion rate register value to 7 for all G78x chips to avoid the problem. Fixes: ae544f64cc7b ("hwmon: (lm90) Add support for GMT G781") Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin --- diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c index 30a7f7fde6511..033c89f8359d1 100644 --- a/drivers/hwmon/lm90.c +++ b/drivers/hwmon/lm90.c @@ -359,7 +359,7 @@ static const struct lm90_params lm90_params[] = { .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT | LM90_HAVE_BROKEN_ALERT, .alert_alarms = 0x7c, - .max_convrate = 8, + .max_convrate = 7, }, [lm86] = { .flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,