5.4-stable review patch. If anyone has any objections, please let me know.
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From: H. Nikolaus Schaller hns@goldelico.com
commit 1e451977e1703b6db072719b37cd1b8e250b9cc9 upstream.
There are fuel gauges in the bq27xxx series (e.g. bq27z561) which may in some cases report 0xff as the value of BQ27XXX_REG_FLAGS that should not be interpreted as "no battery" like for a disconnected battery with some built in bq27000 chip.
So restrict the no-battery detection originally introduced by
commit 3dd843e1c26a ("bq27000: report missing device better.")
to the bq27000.
There is no need to backport further because this was hidden before
commit f16d9fb6cf03 ("power: supply: bq27xxx: Retrieve again when busy")
Fixes: f16d9fb6cf03 ("power: supply: bq27xxx: Retrieve again when busy") Suggested-by: Jerry Lv Jerry.Lv@axis.com Cc: stable@vger.kernel.org Signed-off-by: H. Nikolaus Schaller hns@goldelico.com Link: https://lore.kernel.org/r/dd979fa6855fd051ee5117016c58daaa05966e24.175594529... Signed-off-by: Sebastian Reichel sebastian.reichel@collabora.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/power/supply/bq27xxx_battery.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/power/supply/bq27xxx_battery.c +++ b/drivers/power/supply/bq27xxx_battery.c @@ -1552,8 +1552,8 @@ static void bq27xxx_battery_update_unloc bool has_singe_flag = di->opts & BQ27XXX_O_ZERO;
cache.flags = bq27xxx_read(di, BQ27XXX_REG_FLAGS, has_singe_flag); - if ((cache.flags & 0xff) == 0xff) - cache.flags = -ENODEV; /* read error */ + if (di->chip == BQ27000 && (cache.flags & 0xff) == 0xff) + cache.flags = -ENODEV; /* bq27000 hdq read error */ if (cache.flags >= 0) { cache.temperature = bq27xxx_battery_read_temperature(di); if (has_ci_flag && (cache.flags & BQ27000_FLAG_CI)) {