[PATCH] i2c: i2c-qcom-geni: Fix runtime PM mismatch with child devices

From: Stephen Boyd
Date: Fri Nov 02 2018 - 14:35:42 EST


We need to enable runtime PM on this i2c controller before populating
child devices with i2c_add_adapter(). Otherwise, if a child device uses
runtime PM and stays runtime PM enabled we'll get the following warning
at boot.

Enabling runtime PM for inactive device (a98000.i2c) with active children
WARNING: CPU: 4 PID: 1 at drivers/base/power/runtime.c:1300 pm_runtime_enable+0xd8/0xf8
Modules linked in:
CPU: 4 PID: 1 Comm: swapper/0 Not tainted 4.19.0 #6
elants_i2c 14-0010: 14-0010 supply vccio not found, using dummy regulator
pstate: 60c00089 (nZCv daIf +PAN +UAO)
pc : pm_runtime_enable+0xd8/0xf8
lr : pm_runtime_enable+0xd8/0xf8
sp : ffffffc0de257a30
x29: ffffffc0de257a30 x28: 0000000000061a80
x27: ffffff9008ea7118
x26: ffffffc0d718b058
x25: ffffff9008ea7000 x24: ffffffc0d718a8dc
x23: ffffffc0d718a8b0 x22: ffffffc0d823dd58
x21: 0000000000000000 x20: ffffffc0d823dbc8
x19: ffffffc0d823da90 x18: 000000007f743d9a
x17: 0000000000000080 x16: 0000000000000003
x15: 000000000000003f x14: 0720072007200720
x13: 0720072007200720 x12: 0720072007200720
x11: 0720072007200720 x10: 0720072007200720
x9 : 0720072007200720 x8 : 0720072007200720
x7 : ffffff900816da30 x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000003
x3 : ffffff900816f304 x2 : ffffffc0de248050
x1 : 25045a74f48a7400 x0 : 25045a74f48a7400
Call trace:
pm_runtime_enable+0xd8/0xf8
geni_i2c_probe+0x440/0x460
platform_drv_probe+0x74/0xc8
really_probe+0x1ac/0x35c
driver_probe_device+0xd4/0x118
__driver_attach+0xc8/0x118
bus_for_each_dev+0xac/0xe8
driver_attach+0x38/0x44
bus_add_driver+0x15c/0x294
driver_register+0x13c/0x198
__platform_driver_register+0x88/0x94
geni_i2c_driver_init+0x20/0x28
do_one_initcall+0x250/0x4ec
kernel_init_freeable+0x6f0/0x7c4
kernel_init+0x18/0x120
ret_from_fork+0x10/0x18

Let's move the runtime PM enabling and setup to before we add the
adapter, so that this device can respond to runtime PM requests from
children.

Cc: Douglas Anderson <dianders@xxxxxxxxxxxx>
Cc: Alok Chauhan <alokc@xxxxxxxxxxxxxx>
Fixes: 37692de5d523 ("i2c: i2c-qcom-geni: Add bus driver for the Qualcomm GENI I2C controller")
Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-qcom-geni.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
index 527f55c8c4c7..145eb98ac8b4 100644
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -571,18 +571,19 @@ static int geni_i2c_probe(struct platform_device *pdev)

dev_dbg(&pdev->dev, "i2c fifo/se-dma mode. fifo depth:%d\n", tx_depth);

- ret = i2c_add_adapter(&gi2c->adap);
- if (ret) {
- dev_err(&pdev->dev, "Error adding i2c adapter %d\n", ret);
- return ret;
- }
-
gi2c->suspended = 1;
pm_runtime_set_suspended(gi2c->se.dev);
pm_runtime_set_autosuspend_delay(gi2c->se.dev, I2C_AUTO_SUSPEND_DELAY);
pm_runtime_use_autosuspend(gi2c->se.dev);
pm_runtime_enable(gi2c->se.dev);

+ ret = i2c_add_adapter(&gi2c->adap);
+ if (ret) {
+ dev_err(&pdev->dev, "Error adding i2c adapter %d\n", ret);
+ pm_runtime_disable(gi2c->se.dev);
+ return ret;
+ }
+
return 0;
}

--
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