[PATCH 3/4] i2c: core: treat EPROBE_DEFER when acquiring SCL/SDA GPIOs

From: Codrin Ciubotariu
Date: Tue Aug 04 2020 - 06:02:12 EST


Even if I2C bus GPIO recovery is optional, devm_gpiod_get() can return
-EPROBE_DEFER, so we should at least treat that. This ends up with
i2c_register_adapter() to be able to return -EPROBE_DEFER.

Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@xxxxxxxxxxxxx>
---

Changes from RFC:
- return -EINVAL if i2c_init_recovery() doesn't have the complete
information;
- 'else if' added when checking if i2c_generic_scl_recovery() is used;
- moved i2c_init_recovery() before class-link creation; class-link
cleanup removed;
- moved debug print when the adapter is probed after call to
i2c_init_recovery();

drivers/i2c/i2c-core-base.c | 26 ++++++++++++++------------
1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index cf0c5eb152e1..99dbaead269e 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -375,15 +375,16 @@ static int i2c_gpio_init_recovery(struct i2c_adapter *adap)
return i2c_gpio_init_generic_recovery(adap);
}

-static void i2c_init_recovery(struct i2c_adapter *adap)
+static int i2c_init_recovery(struct i2c_adapter *adap)
{
struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
char *err_str;

if (!bri)
- return;
+ return 0;

- i2c_gpio_init_recovery(adap);
+ if (i2c_gpio_init_recovery(adap) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;

if (!bri->recover_bus) {
err_str = "no recover_bus() found";
@@ -399,10 +400,7 @@ static void i2c_init_recovery(struct i2c_adapter *adap)
if (gpiod_get_direction(bri->sda_gpiod) == 0)
bri->set_sda = set_sda_gpio_value;
}
- return;
- }
-
- if (bri->recover_bus == i2c_generic_scl_recovery) {
+ } else if (bri->recover_bus == i2c_generic_scl_recovery) {
/* Generic SCL recovery */
if (!bri->set_scl || !bri->get_scl) {
err_str = "no {get|set}_scl() found";
@@ -414,10 +412,12 @@ static void i2c_init_recovery(struct i2c_adapter *adap)
}
}

- return;
+ return 0;
err:
dev_err(&adap->dev, "Not using recovery: %s\n", err_str);
adap->bus_recovery_info = NULL;
+
+ return -EINVAL;
}

static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client)
@@ -1444,12 +1444,16 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
if (res)
goto out_reg;

- dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
-
pm_runtime_no_callbacks(&adap->dev);
pm_suspend_ignore_children(&adap->dev, true);
pm_runtime_enable(&adap->dev);

+ res = i2c_init_recovery(adap);
+ if (res == -EPROBE_DEFER)
+ goto out_reg;
+
+ dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
+
#ifdef CONFIG_I2C_COMPAT
res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev,
adap->dev.parent);
@@ -1458,8 +1462,6 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
"Failed to create compatibility class link\n");
#endif

- i2c_init_recovery(adap);
-
/* create pre-declared device nodes */
of_i2c_register_devices(adap);
i2c_acpi_register_devices(adap);
--
2.25.1