On Tue, 9 Oct 2012 14:09:00 -0700, Guenter Roeck wrote:
> Make the code easier to extend and easier to adjust by using a model table
> listing CPU models, stepping/mask, and associated TjMax.
>
> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> ---
> drivers/hwmon/coretemp.c | 36 ++++++++++++++++++++++--------------
> 1 file changed, 22 insertions(+), 14 deletions(-)
I like the idea. Just a couple things about the implementation:
> diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
> index 1937cd4..7107096 100644
> --- a/drivers/hwmon/coretemp.c
> +++ b/drivers/hwmon/coretemp.c
> @@ -208,6 +208,23 @@ static const struct tjmax __cpuinitconst tjmax_table[] = {
> { "CPU 330", 125000 },
> };
>
> +struct tjmax_model {
> + u8 model;
> + u8 mask;
> + int tjmax;
> +};
> +
> +static const struct tjmax_model __cpuinitconst tjmax_model_table[] = {
> + { 0x1c, 10, 100000 }, /* D4xx, N4xx, D5xx, N5xx */
> + { 0x1c, 0, 90000 }, /* Z5xx, N2xx, 230, 330, others */
I don't think the 230 and 330 should be listed there, as they are
overridden by an earlier match in tjmax_table[].
> + { 0x26, 0, 90000 }, /* Atom Tunnel Creek (Exx), Lincroft (Z6xx)
> + * Note: TjMax for E6xxT is 110C, but CPU type
> + * is undetectable by software
> + */
> + { 0x27, 0, 90000 }, /* Atom Medfield (Z2460) */
> + { 0x36, 0, 100000 }, /* Atom Cedar Trail/Cedarview (N2xxx, D2xxx) */
> +};
Using 0 as a special value may be problematic, as I think it is a
possible stepping value:
http://openbenchmarking.org/system/1109120-IV-TSCP1539338/tscp1/cpuinfo
(I agree model name looks odd, not sure if it is a public model or some
engineering sample.)
In hwmon-vid we have:
#define ANY 0xFF
and we use that when the stepping doesn't matter. Note that we also
support stepping ranges there, maybe we'll need it for coretemp too
some day, but I guess we can add it then.
> +
> static int __cpuinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id,
> struct device *dev)
> {
> @@ -226,20 +243,11 @@ static int __cpuinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id,
> return tjmax_table[i].tjmax;
> }
>
> - /* Atom CPUs */
> -
> - if (c->x86_model == 0x1c) {
> - /*
> - * TjMax for stepping 10 CPUs (N4xx, N5xx, D4xx, D5xx)
> - * is 100 degrees C, for all others it is 90 degrees C.
> - */
> - if (c->x86_mask == 10)
> - return 100000;
> - return 90000;
> - } else if (c->x86_model == 0x26 || c->x86_model == 0x27) {
> - return 90000;
> - } else if (c->x86_model == 0x36) {
> - return 100000;
> + for (i = 0; i < ARRAY_SIZE(tjmax_model_table); i++) {
> + const struct tjmax_model *tm = &tjmax_model_table[i];
> + if (c->x86_model == tm->model &&
> + (!tm->mask || c->x86_mask == tm->mask))
> + return tm->tjmax;
> }
>
> /* Early chips have no MSR for TjMax */
Other than these implementation details:
Acked-by: Jean Delvare <khali@xxxxxxxxxxxx>
--
Jean Delvare
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