On 04/14/2016 03:53 PM, Jisheng Zhang wrote:
When pm_runtime_enable() was being called, the device's usage counter
was 0, causing the PM layer to runtime-suspend the device. We then
went on to call i2c_dw_probe() on a suspended device, which could hung.
Fix this by incrementing the usage counter before pm_runtime_enable().
Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxxx>
---
drivers/i2c/busses/i2c-designware-platdrv.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index d656657..00f9e99 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -246,6 +246,7 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
if (dev->pm_runtime_disabled) {
pm_runtime_forbid(&pdev->dev);
} else {
+ pm_runtime_get_noresume(&pdev->dev);
pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
pm_runtime_use_autosuspend(&pdev->dev);
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable() here after pm_runtime_set_active() shouldn't suspend
as far as I understand which made me thinking if there is some other
issue that cause the symptoms what you are seeing? Like race with
runtime PM or similar.
--
Jarkko
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