On Mon, Sep 11, 2017 at 06:41:56PM -0700, Patrick Venture wrote: > On Mon, Sep 11, 2017 at 4:56 PM, Joel Stanley <joel@xxxxxxxxx> wrote: > > > Hi Patrick, > > > > On Tue, Sep 12, 2017 at 8:41 AM, Patrick Venture <venture@xxxxxxxxxx> > > wrote: > > > The previous value reduced the time required to determine > > > the fan value, however, it's also used as the final timeout > > > mechanism. The prevous value would work for any fan speed > > > greater than around 3k RPM. This increased value, lets the fan > > > speeds return quickly but will wait longer to handle speeds below 3k > > > RPM. > > > > Given you've had to tweak this value a few times, should we instead > > make it a device tree property? > > > > We could still use the result of your findings to provide a sensible > > default, but machines that have specific fan configurations could use > > the property to tweak the driver. > > > > I had a todo item in my last commit for this field to do just that -- make > it a variable. I'm perfectly willing to head down this path. I found that > my previous value was too aggressive for those slow speeds for the > timeout. This path addresses that. I think though this new value, does > make for a good default value as you've commented. I have some cycles > coming up to move this value into something that can be set in a device > tree. > You'll have tto find a means to explain that this is not a configuration parameter but a system property. Either case, I am hesitant to update this again. This seems to be an endless exercise. How do I know that this won't go on forever ? Guenter > > > > Cheers, > > > > Joel > > > > > > > > Testing: this value was determined through experimentation on the ast2400 > > > on the Quanta-q71l. This configurations runs 8 fans attached to the > > > controller. > > > > > > Signed-off-by: Patrick Venture <venture@xxxxxxxxxx> > > > --- > > > drivers/hwmon/aspeed-pwm-tacho.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/hwmon/aspeed-pwm-tacho.c > > b/drivers/hwmon/aspeed-pwm-tacho.c > > > index 69b97d45e3cb..f914e5f41048 100644 > > > --- a/drivers/hwmon/aspeed-pwm-tacho.c > > > +++ b/drivers/hwmon/aspeed-pwm-tacho.c > > > @@ -161,7 +161,7 @@ > > > * 11: reserved. > > > */ > > > #define M_TACH_MODE 0x02 /* 10b */ > > > -#define M_TACH_UNIT 0x00c0 > > > +#define M_TACH_UNIT 0x0210 > > > #define INIT_FAN_CTRL 0xFF > > > > > > /* How long we sleep in us while waiting for an RPM result. */ > > > -- > > > 2.14.1.581.gf28d330327-goog > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
