Messages in this thread | | | Date | Sat, 29 Nov 2014 16:12:07 -0800 | From | Guenter Roeck <> | Subject | Re: [PATCH] i8k: Fix temperature bug handling in i8k_get_temp() |
| |
On Tue, Nov 18, 2014 at 03:56:54PM +0100, Pali Rohár wrote: > Static array prev[] was incorrectly initialized. It should be initialized to > some "invalid" temperature value (above I8K_MAX_TEMP). > > Next, function should store "invalid" value to prev[] (above I8K_MAX_TEMP), > not valid (= I8K_MAX_TEMP) because whole temperature bug handling will not > work. > > And last part, to not break existing detection of temperature sensors, register > them also if i8k report too high temperature (above I8K_MAX_TEMP). This is > needed because some sensors are sometimes turned off (e.g sensor on GPU which > can be turned off/on) and in this case SMM report too high value. > > To prevent reporting "invalid" values to userspace, return -EINVAL. In this case > sensors which are currently turned off (e.g optimus/powerexpress/enduro gpu) > are reported as "N/A" by lm-sensors package. > > Signed-off-by: Pali Rohár <pali.rohar@gmail.com> > --- > drivers/char/i8k.c | 16 ++++++++++------ > 1 file changed, 10 insertions(+), 6 deletions(-) > > diff --git a/drivers/char/i8k.c b/drivers/char/i8k.c > index 7272b08..e34a019 100644 > --- a/drivers/char/i8k.c > +++ b/drivers/char/i8k.c > @@ -298,7 +298,7 @@ static int i8k_get_temp(int sensor) > int temp; > > #ifdef I8K_TEMPERATURE_BUG > - static int prev[4]; > + static int prev[4] = { I8K_MAX_TEMP+1, I8K_MAX_TEMP+1, I8K_MAX_TEMP+1, I8K_MAX_TEMP+1 };
This results in a checkpatch warning. Please split, and add a space before and after '+'. Actually, I would suggest to use something something like
#define I8K_INVALID_TEMP (I8K_MAX_TEMP + 1)
and to use it instead of hard-coding "I8K_MAX_TEMP + 1" in the code.
> #endif > regs.ebx = sensor & 0xff; > rc = i8k_smm(®s); > @@ -317,10 +317,12 @@ static int i8k_get_temp(int sensor) > */ > if (temp > I8K_MAX_TEMP) { > temp = prev[sensor]; > - prev[sensor] = I8K_MAX_TEMP; > + prev[sensor] = I8K_MAX_TEMP+1; > } else { > prev[sensor] = temp; > } > + if (temp > I8K_MAX_TEMP) > + return -ERANGE; > #endif > > return temp; > @@ -499,6 +501,8 @@ static ssize_t i8k_hwmon_show_temp(struct device *dev, > int temp; > > temp = i8k_get_temp(index); > + if (temp == -ERANGE) > + return -EINVAL; > if (temp < 0) > return temp; > return sprintf(buf, "%d\n", temp * 1000); > @@ -610,17 +614,17 @@ static int __init i8k_init_hwmon(void) > > /* CPU temperature attributes, if temperature reading is OK */ > err = i8k_get_temp(0); > - if (err >= 0) > + if (err >= 0 || err == -ERANGE) > i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1; > /* check for additional temperature sensors */ > err = i8k_get_temp(1); > - if (err >= 0) > + if (err >= 0 || err == -ERANGE) > i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP2; > err = i8k_get_temp(2); > - if (err >= 0) > + if (err >= 0 || err == -ERANGE) > i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP3; > err = i8k_get_temp(3); > - if (err >= 0) > + if (err >= 0 || err == -ERANGE) > i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4; > > /* Left fan attributes, if left fan is present */ > -- > 1.7.9.5 >
| |