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| author | Andre Przywara <andre.przywara@amd.com> | 2012-03-23 10:02:17 +0100 |
|---|---|---|
| committer | Jean Delvare <khali@endymion.delvare> | 2012-03-23 10:02:17 +0100 |
| commit | 941a956b0e387b21f385f486c34ef67576775cfc (patch) | |
| tree | 35d118d214a7c4d57ef1f8b085cafc9725255b75 /drivers/hwmon/fam15h_power.c | |
| parent | hwmon: (fam15h_power) Correct sign extension of running_avg_capture (diff) | |
| download | linux-941a956b0e387b21f385f486c34ef67576775cfc.tar.xz linux-941a956b0e387b21f385f486c34ef67576775cfc.zip | |
hwmon: (fam15h_power) Increase output resolution
On high CPU load the accumulating values in the running_avg_cap
register are very low (below 10), so averaging them too early leads
to unnecessary poor output resolution. Since we pretend to output
micro-Watt we better keep all the bits we have as long as possible.
Signed-off-by: Andre Przywara <andre.przywara@amd.com>
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'drivers/hwmon/fam15h_power.c')
| -rw-r--r-- | drivers/hwmon/fam15h_power.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/hwmon/fam15h_power.c b/drivers/hwmon/fam15h_power.c index 930370de5201..b7494af1e4a9 100644 --- a/drivers/hwmon/fam15h_power.c +++ b/drivers/hwmon/fam15h_power.c @@ -61,14 +61,14 @@ static ssize_t show_power(struct device *dev, REG_TDP_RUNNING_AVERAGE, &val); running_avg_capture = (val >> 4) & 0x3fffff; running_avg_capture = sign_extend32(running_avg_capture, 21); - running_avg_range = val & 0xf; + running_avg_range = (val & 0xf) + 1; pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5), REG_TDP_LIMIT3, &val); tdp_limit = val >> 16; - curr_pwr_watts = tdp_limit + data->base_tdp - - (s32)(running_avg_capture >> (running_avg_range + 1)); + curr_pwr_watts = (tdp_limit + data->base_tdp) << running_avg_range; + curr_pwr_watts -= running_avg_capture; curr_pwr_watts *= data->tdp_to_watts; /* @@ -78,7 +78,7 @@ static ssize_t show_power(struct device *dev, * scaling factor 1/(2^16). For conversion we use * (10^6)/(2^16) = 15625/(2^10) */ - curr_pwr_watts = (curr_pwr_watts * 15625) >> 10; + curr_pwr_watts = (curr_pwr_watts * 15625) >> (10 + running_avg_range); return sprintf(buf, "%u\n", (unsigned int) curr_pwr_watts); } static DEVICE_ATTR(power1_input, S_IRUGO, show_power, NULL); |