Messages in this thread | | | Date | Thu, 02 Nov 2006 12:49:54 -0500 | From | Bill Davidsen <> | Subject | Re: [ltp] Re: [PATCH v2] Re: Battery class driver. |
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Henrique de Moraes Holschuh wrote: > On Wed, 01 Nov 2006, Greg KH wrote: >> On Wed, Nov 01, 2006 at 09:53:12PM +0200, Shem Multinymous wrote: >>> Hi Greg, >>> >>> On 11/1/06, Greg KH <greg@kroah.com> wrote: >>>>> The suggestions so far were: >>>>> 1. Append units string to the content of such attribute: >>>>> /sys/.../capacity_remaining reads "16495 mW". >>>>> 2. Add a seprate *_units attribute saying what are units for other >>>>> attribute: >>>>> /sys/.../capacity_units gives the units for >>>>> /sys/.../capacity_{remaining,last_full,design,min,...}. >>>>> 3. Append the units to the attribute names: >>>>> capacity_{remaining,last_full,design_min,...}:mV. >>>> No, again, one for power and one for current. Two different files >>>> depending on the type of battery present. That way there is no need to >>>> worry about unit issues. >>> I'm missing something. How is that different from option 3 above? >> No silly ":mV" on the file name. > > As long as that also means no "silly _mV" in the name. However, if the > choice is between :mV and _mV, please go with :mV. > >>> BTW, please note that we're talking about a large set of files that >>> use these units (remaining, last full, design capacity, alarm >>> thresholds, etc.), and not just a single attribute. >> Sure, what's wrong with: >> capacity_remaining_power >> capacity_last_full_power >> capacity_design_min_power >> if you can read that from the battery, and: >> capacity_remaining_current >> capacity_last_full_current >> capacity_design_min_current >> if you can read that instead. > > Well, "Wh" measures energy and not power, and "Ah" measures electric charge > and not current, so it would be better to make that: > > capacity_*_energy (Wh-based) > > and > > capacity_*_charge (Ah-based) > > Also, should we go with mWh/mAh, or with even smaller units because of the > tiny battery-driven devices of tomorrow? > Having seen a French consultant with a Windows laptop reporting mJ (Joules) I bet that came from the hardware. And given that laptop batteries run at (almost) constant voltage, could all of these just be converted to mWh for consistency?
-- Bill Davidsen <davidsen@tmr.com> Obscure bug of 2004: BASH BUFFER OVERFLOW - if bash is being run by a normal user and is setuid root, with the "vi" line edit mode selected, and the character set is "big5," an off-by-one errors occurs during wildcard (glob) expansion. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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