On 3/28/2016 6:05 AM, Daniel Kurtz wrote:

+Rhyland Klein who original wrote this code...

On Mon, Mar 28, 2016 at 10:32 AM, YH Huang [off-list ref] wrote:

quoted

On Fri, 2016-03-25 at 11:06 +0800, Daniel Kurtz wrote:

quoted

On Thu, Mar 24, 2016 at 2:43 PM, YH Huang [off-list ref] wrote:

quoted

Hi Daniel,

On Thu, 2016-03-24 at 12:01 +0800, Daniel Kurtz wrote:

quoted

Hi YH,

On Wed, Mar 23, 2016 at 5:53 PM, YH Huang [off-list ref] wrote:

quoted

When the battery is dry and BATTERY_FULL_DISCHARGED is set,
we should check BATTERY_DISCHARGING to decide the power status.
If BATTERY_DISCHARGING is set, the power status is not charging.
Or the power status should be charging.

Signed-off-by: YH Huang <redacted>
---
 drivers/power/sbs-battery.c |   22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/power/sbs-battery.c b/drivers/power/sbs-battery.c
index d6226d6..d86db0e 100644
--- a/drivers/power/sbs-battery.c
+++ b/drivers/power/sbs-battery.c

@@ -382,11 +382,12 @@ static int sbs_get_battery_property(struct i2c_client *client,

                if (ret & BATTERY_FULL_CHARGED)
                        val->intval = POWER_SUPPLY_STATUS_FULL;
-               else if (ret & BATTERY_FULL_DISCHARGED)
-                       val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
-               else if (ret & BATTERY_DISCHARGING)
-                       val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
-               else
+               else if (ret & BATTERY_DISCHARGING) {
+                       if (ret & BATTERY_FULL_DISCHARGED)
+                               val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+                       else
+                               val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+               } else

I think (BATTERY_DISCHARGING && BATTERY_FULL_DISCHARGED) is still
POWER_SUPPLY_STATUS_DISCHARGING.
So, let's just report what the battery says and do:

               else if (ret & BATTERY_DISCHARGING)
                               val->intval = POWER_SUPPLY_STATUS_DISCHARGING;

So we just ignore the special situation (BATTERY_DISCHARGING &&
BATTERY_FULL_DISCHARGED).
Isn't POWER_SUPPLY_STATUS_NOT_CHARGING a useful information?

The battery is discharging.  The fact that it is also reporting that
it is already "discharged" just seems premature.   I would expect to
only see NOT_CHARGING if completely discharged *and* not discharging.

I check the "Smart Battery Data Specification Revision 1.1".
And there are some words about FULLY_DISCHARGED.
"Discharge should be stopped soon."
"This status bit may be set prior to the
?TERMINATE_DISCHARGE_ALARM? as an early or first level warning of end of
battery charge."
It looks like the FULLY_DISCHARGED status is used to announce the
warning of battery charge and it is still discharging if there is no one
takes care of it.

The only difference I see in the patch above is that in the case where
DISCHARGING isn't set, it won't check FULL_DISCHARGE. Nothing seems to
be changed in the case where FULL_DISCHARGE & DISCHARGING are set.

I think in the case that both flags are set, it makes sense to
prioritize the FULL_DISCHARGE, since as quote above actually starts with
"FULLY_DISCHARGED bit is set when the Smart Battery determines that it
has supplied all the charge it can." I think at the point where both
statuses are reported, the fact that it is still DISCHARGING doesn't
matter. The code as is handles this in that manner, so I don't see a
need to change it.

-rhyland


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