power: supply: sbs-battery: only return health when battery present

when the battery is set to sbs-mode and  no gpio detection is enabled
"health" is always returning a value even when the battery is not present.
All other fields return "not present".
This leads to a scenario where the driver is constantly switching between
"present" and "not present" state. This generates a lot of constant
traffic on the i2c.

This commit changes the response of "health" to an error when the battery
is not responding leading to a consistent "not present" state.

Fixes: 76b16f4cdfb8 ("power: supply: sbs-battery: don't assume MANUFACTURER_DATA formats")
Cc: <stable@vger.kernel.org>
Signed-off-by: Michael Nosthoff <committed@heine.so>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Tested-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

diff --git a/drivers/power/supply/sbs-battery.c b/drivers/power/supply/sbs-battery.c
index 2e86cc1..f8d74e9 100644 (file)
--- a/drivers/power/supply/sbs-battery.c
+++ b/drivers/power/supply/sbs-battery.c
@@ -314,17 +314,22 @@ static int sbs_get_battery_presence_and_health(
 {
        int ret;
 
-       if (psp == POWER_SUPPLY_PROP_PRESENT) {
-               /* Dummy command; if it succeeds, battery is present. */
-               ret = sbs_read_word_data(client, sbs_data[REG_STATUS].addr);
-               if (ret < 0)
-                       val->intval = 0; /* battery disconnected */
-               else
-                       val->intval = 1; /* battery present */
-       } else { /* POWER_SUPPLY_PROP_HEALTH */
+       /* Dummy command; if it succeeds, battery is present. */
+       ret = sbs_read_word_data(client, sbs_data[REG_STATUS].addr);
+
+       if (ret < 0) { /* battery not present*/
+               if (psp == POWER_SUPPLY_PROP_PRESENT) {
+                       val->intval = 0;
+                       return 0;
+               }
+               return ret;
+       }
+
+       if (psp == POWER_SUPPLY_PROP_PRESENT)
+               val->intval = 1; /* battery present */
+       else /* POWER_SUPPLY_PROP_HEALTH */
                /* SBS spec doesn't have a general health command. */
                val->intval = POWER_SUPPLY_HEALTH_UNKNOWN;
-       }
 
        return 0;
 }
@@ -626,6 +631,8 @@ static int sbs_get_property(struct power_supply *psy,
                else
                        ret = sbs_get_battery_presence_and_health(client, psp,
                                                                  val);
+
+               /* this can only be true if no gpio is used */
                if (psp == POWER_SUPPLY_PROP_PRESENT)
                        return 0;
                break;