Hi Bryan,
On 5/24/22 17:02, Bryan O'Donoghue wrote:
When we compile-in the CCI along with the imx412 driver and run on the RB5
we see that i2c_add_adapter() causes the probe of the imx412 driver to
happen.
This probe tries to perform an i2c xfer() and the xfer() in i2c-qcom-cci.c
fails on pm_runtime_get() because the i2c-qcom-cci.c::probe() function has
not completed to pm_runtime_enable(dev).
Fix this sequence by ensuring pm_runtime_xxx() calls happen prior to adding
the i2c adapter.
it's a proper root cause disclosure and the fix, thank you.
Fixes: e517526195de ("i2c: Add Qualcomm CCI I2C driver")
Reported-by: Vladimir Zapolskiy <vladimir.zapolskiy@xxxxxxxxxx>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-qcom-cci.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/drivers/i2c/busses/i2c-qcom-cci.c b/drivers/i2c/busses/i2c-qcom-cci.c
index 5c7cc862f08f..90d02effeae9 100644
--- a/drivers/i2c/busses/i2c-qcom-cci.c
+++ b/drivers/i2c/busses/i2c-qcom-cci.c
@@ -638,6 +638,11 @@ static int cci_probe(struct platform_device *pdev)
if (ret < 0)
goto error;
+ pm_runtime_set_autosuspend_delay(dev, MSEC_PER_SEC);
+ pm_runtime_use_autosuspend(dev);
+ pm_runtime_set_active(dev);
+ pm_runtime_enable(dev);
+
for (i = 0; i < cci->data->num_masters; i++) {
if (!cci->master[i].cci)
continue;
@@ -649,14 +654,13 @@ static int cci_probe(struct platform_device *pdev)
}
}
- pm_runtime_set_autosuspend_delay(dev, MSEC_PER_SEC);
- pm_runtime_use_autosuspend(dev);
- pm_runtime_set_active(dev);
- pm_runtime_enable(dev);
-
return 0;
error_i2c:
+ pm_runtime_put(dev);
Here pm_runtime_put(dev) should be removed, there is no pm_runtime_get*(dev) above,
otherwise PM usage counter underflow issues are expected.
+ pm_runtime_disable(dev);
+ pm_runtime_dont_use_autosuspend(dev);
+
for (--i ; i >= 0; i--) {
if (cci->master[i].cci) {
i2c_del_adapter(&cci->master[i].adap);
With the correction stated above please feel free to add my tags:
Reviewed-by: Vladimir Zapolskiy <vladimir.zapolskiy@xxxxxxxxxx>
Tested-by: Vladimir Zapolskiy <vladimir.zapolskiy@xxxxxxxxxx>
--
Best wishes,
Vladimir
