Re: [PATCH] hwmon: (fam15h_power) Add bit masking for tdp_limit

From: Borislav Petkov
Date: Wed Jan 27 2016 - 06:13:06 EST


On Wed, Jan 27, 2016 at 12:02:09PM +0100, Gioh Kim wrote:
> Add bit masking to read ApmTdpLimit precisely
>
> Signed-off-by: Gioh Kim <gi-oh.kim@xxxxxxxxxxxxxxxx>
> ---
> drivers/hwmon/fam15h_power.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hwmon/fam15h_power.c b/drivers/hwmon/fam15h_power.c
> index f77eb97..4f695d8 100644
> --- a/drivers/hwmon/fam15h_power.c
> +++ b/drivers/hwmon/fam15h_power.c
> @@ -90,7 +90,15 @@ static ssize_t show_power(struct device *dev,
> pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
> REG_TDP_LIMIT3, &val);
>
> - tdp_limit = val >> 16;
> + /*
> + * On Carrizo and later platforms, ApmTdpLimit bit field
> + * is extended to 16:31 from 16:28.
> + */
> + if (boot_cpu_data.x86 == 0x15 && boot_cpu_data.x86_model >= 0x60)
> + tdp_limit = val >> 16;
> + else
> + tdp_limit = (val >> 16) & 0x1fff;
> +
> curr_pwr_watts = ((u64)(tdp_limit +
> data->base_tdp)) << running_avg_range;
> curr_pwr_watts -= running_avg_capture;
> --

Acked-by: Borislav Petkov <bp@xxxxxxx>

Btw, Rui, you could consider unifying the code under a single

if (boot_cpu_data.x86 == 0x15 && boot_cpu_data.x86_model >= 0x60) {
...

else
...

as with this patch you'll have two of those checks. Unified might be
better readable but that is for another patch.

Thanks.

--
Regards/Gruss,
Boris.

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