From eb88577ee485d5e9f180c307e4bdcb7fe42d81c1 Mon Sep 17 00:00:00 2001 From: Michael Auchter Date: Tue, 10 Mar 2020 15:58:40 -0500 Subject: [PATCH] misc: eeprom: at24: fix regulator underflow The at24 driver attempts to read a byte from the device to validate that it's actually present, and if not, disables the vcc regulator and returns -ENODEV. However, between the read and the error handling path, pm_runtime_idle() is called and invokes the driver's suspend callback, which also disables the vcc regulator. This leads to an underflow of the regulator enable count if the EEPROM is not present. Move the pm_runtime_suspend() call to be after the error handling path to resolve this. Fixes: 47f4d15e3435 ("misc: eeprom: at24: support pm_runtime control") Signed-off-by: Michael Auchter Signed-off-by: Bartosz Golaszewski --- drivers/misc/eeprom/at24.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index 031eb64549af5..282c9ef68ed22 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -712,13 +712,14 @@ static int at24_probe(struct i2c_client *client) * chip is functional. */ err = at24_read(at24, 0, &test_byte, 1); - pm_runtime_idle(dev); if (err) { pm_runtime_disable(dev); regulator_disable(at24->vcc_reg); return -ENODEV; } + pm_runtime_idle(dev); + if (writable) dev_info(dev, "%u byte %s EEPROM, writable, %u bytes/write\n", byte_len, client->name, at24->write_max); -- 2.39.5