2010-11-05 02:36:14

by Guenter Roeck

Subject: Re: [lm-sensors] [PATCH 4/8] hwmon: applesmc: Handle new temperature format

On Sun, Oct 31, 2010 at 03:50:30AM -0400, Henrik Rydberg wrote:
> The recent Macbooks have temperature registers of a new type.
> This patch adds the logic to handle them.
>
> Signed-off-by: Henrik Rydberg <[email protected]>
> ---
> drivers/hwmon/applesmc.c | 12 +++++++++---
> 1 files changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c
> index 0207618..ec92aff 100644
> --- a/drivers/hwmon/applesmc.c
> +++ b/drivers/hwmon/applesmc.c
> @@ -733,13 +733,19 @@ static ssize_t applesmc_show_temperature(struct device *dev,
> ret = applesmc_get_entry_by_index(index, &entry);
> if (ret)
> return ret;
> + if (entry.len > 2)
> + return -EINVAL;
>
> - ret = applesmc_read_entry(&entry, buffer, 2);
> + ret = applesmc_read_entry(&entry, buffer, entry.len);
> if (ret)
> return ret;
>
> - temp = buffer[0]*1000;
> - temp += (buffer[1] >> 6) * 250;
> + if (entry.len == 2) {
> + temp = buffer[0]*1000;
> + temp += (buffer[1] >> 6) * 250;
> + } else {
> + temp = buffer[0] * 4000;
> + }

Another comment - in the next patch, you check for entry.len == 0.
If that can happen, you would need to check it here as well.

Guenter

2010-11-05 08:35:39

by Henrik Rydberg

Subject: Re: [lm-sensors] [PATCH 4/8] hwmon: applesmc: Handle new temperature format

>>

>> diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c
>> index 0207618..ec92aff 100644
>> --- a/drivers/hwmon/applesmc.c
>> +++ b/drivers/hwmon/applesmc.c
>> @@ -733,13 +733,19 @@ static ssize_t applesmc_show_temperature(struct device *dev,
>> ret = applesmc_get_entry_by_index(index, &entry);
>> if (ret)
>> return ret;
>> + if (entry.len > 2)
>> + return -EINVAL;
>>
>> - ret = applesmc_read_entry(&entry, buffer, 2);
>> + ret = applesmc_read_entry(&entry, buffer, entry.len);
>> if (ret)
>> return ret;
>>
>> - temp = buffer[0]*1000;
>> - temp += (buffer[1] >> 6) * 250;
>> + if (entry.len == 2) {
>> + temp = buffer[0]*1000;
>> + temp += (buffer[1] >> 6) * 250;
>> + } else {
>> + temp = buffer[0] * 4000;
>> + }
>
> Another comment - in the next patch, you check for entry.len == 0.
> If that can happen, you would need to check it here as well.


It cannot happen after a succesful return from get_entry(), but I will check it
again. Earlier versions used entry.len rather than entry.valid, which can still
be seen in a few places.

Thanks,
Henrik