Hello, I have no clue about runtime-pm, but I added a few people to Cc: who should know better ...
Best regards Uwe On Mon, Aug 03, 2015 at 06:15:54PM +0200, Andrew Lunn wrote: > On Mon, Aug 03, 2015 at 05:50:11PM +0200, Lucas Stach wrote: > > The clocks are initially active and thus the device is marked active. > > This still keeps the PM refcount at 0, the pm_runtime_put_autosuspend() > > call at the end of probe then leaves us with an invalid refcount of -1, > > which in turn leads to the device staying in suspended state even though > > netdev open had been called. > > > > Fix this by initializing the refcount to be coherent with the initial > > device status. > > > > Fixes: > > 8fff755e9f8 (net: fec: Ensure clocks are enabled while using mdio bus) > > > > Signed-off-by: Lucas Stach <l.st...@pengutronix.de> > > --- > > Please apply this as a fix for 4.2 > > --- > > drivers/net/ethernet/freescale/fec_main.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/drivers/net/ethernet/freescale/fec_main.c > > b/drivers/net/ethernet/freescale/fec_main.c > > index 32e3807c650e..271bb5862346 100644 > > --- a/drivers/net/ethernet/freescale/fec_main.c > > +++ b/drivers/net/ethernet/freescale/fec_main.c > > @@ -3433,6 +3433,7 @@ fec_probe(struct platform_device *pdev) > > > > pm_runtime_set_autosuspend_delay(&pdev->dev, FEC_MDIO_PM_TIMEOUT); > > pm_runtime_use_autosuspend(&pdev->dev); > > + pm_runtime_get_noresume(&pdev->dev); > > pm_runtime_set_active(&pdev->dev); > > pm_runtime_enable(&pdev->dev); > > This might work, but is it the correct fix? > > Documentation/power/runtime_pm.txt says: > > 534 In addition to that, the initial runtime PM status of all devices is > 535 'suspended', but it need not reflect the actual physical state of the > device. > 536 Thus, if the device is initially active (i.e. it is able to process I/O), > its > 537 runtime PM status must be changed to 'active', with the help of > 538 pm_runtime_set_active(), before pm_runtime_enable() is called for the > device. > > At the point we call the pm_runtime_ functions above, all the clocks > are ticking. So according to the documentation pm_runtime_set_active() > is the right thing to do. But it makes no mention of have to call > pm_runtime_get_noresume(). I would of expected pm_runtime_set_active() > to set the count to the correct value. -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
