If earlyprintk is enabled and current UART is console port the platform
code can mark it as RPM_ACTIVE to sync real IP state with PM Runtime and
avoid resuming of already active device, but now, driver initialization
will be performed in the wrong way:
pm_runtime_enable(&pdev->dev);
<-- PM runtime alowed (device state RPM_ACTIVE)
if (omap_up_info->autosuspend_timeout == 0)
omap_up_info->autosuspend_timeout = -1;
device_init_wakeup(up->dev, true);
pm_runtime_use_autosuspend(&pdev->dev);
<-- update_autosuspend() will be called and it will disable device
(device state RPM_SUSPENDED)
pm_runtime_set_autosuspend_delay(&pdev->dev,
omap_up_info->autosuspend_timeout);
<-- update_autosuspend() will be called which will re-enable device
(device state RPM_ACTIVE), because autosuspend_timeout < 0
pm_runtime_irq_safe(&pdev->dev);
pm_runtime_get_sync(&pdev->dev);
<-- will do nothing
Such behavior isn't expected by OMAP serial drivers and causes
unpredictable calls of serial_omap_runtime_suspend() and
serial_omap_runtime_resume().
Hence, fix it by allowing PM runtime only after all its parameters are
configured.
CC: Tony Lindgren <tony@xxxxxxxxxxx>
CC: Rajendra Nayak <rnayak@xxxxxx>
CC: Felipe Balbi <balbi@xxxxxx>
CC: Kevin Hilman <khilman@xxxxxxxxxx>
Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
---
tested on OMAP4 SDP with and without earlyprintk enabled.
drivers/tty/serial/omap-serial.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index b6d1728..f39bf0c 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1501,7 +1501,6 @@ static int serial_omap_probe(struct platform_device *pdev)
INIT_WORK(&up->qos_work, serial_omap_uart_qos_work);
platform_set_drvdata(pdev, up);
- pm_runtime_enable(&pdev->dev);
if (omap_up_info->autosuspend_timeout == 0)
omap_up_info->autosuspend_timeout = -1;
device_init_wakeup(up->dev, true);
@@ -1510,6 +1509,8 @@ static int serial_omap_probe(struct platform_device *pdev)
omap_up_info->autosuspend_timeout);
pm_runtime_irq_safe(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+
pm_runtime_get_sync(&pdev->dev);
omap_serial_fill_features_erratas(up);
--
1.7.9.5
--
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