From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ulf Hansson Subject: Re: [PATCH 4/7] serial: 8250_omap: Fix PM regression with deferred probe for pm_runtime_reinit Date: Fri, 12 Feb 2016 13:52:09 +0100 Message-ID: References: <1455145370-20301-1-git-send-email-tony@atomide.com> <1455145370-20301-5-git-send-email-tony@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <1455145370-20301-5-git-send-email-tony@atomide.com> Sender: linux-mmc-owner@vger.kernel.org To: Tony Lindgren Cc: linux-omap , "linux-arm-kernel@lists.infradead.org" , linux-serial@vger.kernel.org, Alan Stern , Greg Kroah-Hartman , Kevin Hilman , Nishanth Menon , Peter Hurley , "Rafael J . Wysocki" , Tero Kristo , "linux-i2c@vger.kernel.org" , linux-mmc , "linux-spi@vger.kernel.org" , Mark Brown , Wolfram Sang List-Id: linux-i2c@vger.kernel.org On 11 February 2016 at 00:02, Tony Lindgren wrote: > Commit 5de85b9d57ab ("PM / runtime: Re-init runtime PM states at probe > error and driver unbind") introduced pm_runtime_reinit() that is used > to reinitialize PM runtime after -EPROBE_DEFER. This allows shutting > down the device after a failed probe. > > However, for drivers using pm_runtime_use_autosuspend() this can cause > a state where suspend callback is never called after -EPROBE_DEFER. > On the following device driver probe, hardware state is different from > the PM runtime state causing omap_device to produce the following > error: > > omap_device_enable() called from invalid state 1 > > And with omap_device and omap hardware being picky for PM, this will > block any deeper idle states in hardware. > > The solution is to fix the drivers to follow the PM runtime documentation: > > 1. For sections of code that needs the device disabled, use > pm_runtime_put_sync_suspend() if pm_runtime_set_autosuspend() has > been set. > > 2. For driver exit code, use pm_runtime_dont_use_autosuspend() before > pm_runtime_put_sync() if pm_runtime_use_autosuspend() has been > set. > > Fixes: 5de85b9d57ab ("PM / runtime: Re-init runtime PM states at probe > error and driver unbind") > Cc: linux-serial@vger.kernel.org > Cc: Alan Stern > Cc: Greg Kroah-Hartman > Cc: Kevin Hilman > Cc: Nishanth Menon > Cc: Peter Hurley > Cc: Rafael J. Wysocki > Cc: Ulf Hansson > Cc: Tero Kristo > Signed-off-by: Tony Lindgren Acked-by: Ulf Hansson Kind regards Uffe > --- > > Greg & Peter, I'd like to merge this along with other related fixes > via the ARM SoC tree if no objections, please review and ack if this > look OK to you. > > --- > drivers/tty/serial/8250/8250_omap.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c > index a2c0734..81ff337 100644 > --- a/drivers/tty/serial/8250/8250_omap.c > +++ b/drivers/tty/serial/8250/8250_omap.c > @@ -1235,7 +1235,8 @@ static int omap8250_probe(struct platform_device *pdev) > pm_runtime_put_autosuspend(&pdev->dev); > return 0; > err: > - pm_runtime_put(&pdev->dev); > + pm_runtime_dont_use_autosuspend(&pdev->dev); > + pm_runtime_put_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > return ret; > } > @@ -1244,6 +1245,7 @@ static int omap8250_remove(struct platform_device *pdev) > { > struct omap8250_priv *priv = platform_get_drvdata(pdev); > > + pm_runtime_dont_use_autosuspend(&pdev->dev); > pm_runtime_put_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > serial8250_unregister_port(priv->line); > -- > 2.7.0 > From mboxrd@z Thu Jan 1 00:00:00 1970 From: ulf.hansson@linaro.org (Ulf Hansson) Date: Fri, 12 Feb 2016 13:52:09 +0100 Subject: [PATCH 4/7] serial: 8250_omap: Fix PM regression with deferred probe for pm_runtime_reinit In-Reply-To: <1455145370-20301-5-git-send-email-tony@atomide.com> References: <1455145370-20301-1-git-send-email-tony@atomide.com> <1455145370-20301-5-git-send-email-tony@atomide.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 11 February 2016 at 00:02, Tony Lindgren wrote: > Commit 5de85b9d57ab ("PM / runtime: Re-init runtime PM states at probe > error and driver unbind") introduced pm_runtime_reinit() that is used > to reinitialize PM runtime after -EPROBE_DEFER. This allows shutting > down the device after a failed probe. > > However, for drivers using pm_runtime_use_autosuspend() this can cause > a state where suspend callback is never called after -EPROBE_DEFER. > On the following device driver probe, hardware state is different from > the PM runtime state causing omap_device to produce the following > error: > > omap_device_enable() called from invalid state 1 > > And with omap_device and omap hardware being picky for PM, this will > block any deeper idle states in hardware. > > The solution is to fix the drivers to follow the PM runtime documentation: > > 1. For sections of code that needs the device disabled, use > pm_runtime_put_sync_suspend() if pm_runtime_set_autosuspend() has > been set. > > 2. For driver exit code, use pm_runtime_dont_use_autosuspend() before > pm_runtime_put_sync() if pm_runtime_use_autosuspend() has been > set. > > Fixes: 5de85b9d57ab ("PM / runtime: Re-init runtime PM states at probe > error and driver unbind") > Cc: linux-serial at vger.kernel.org > Cc: Alan Stern > Cc: Greg Kroah-Hartman > Cc: Kevin Hilman > Cc: Nishanth Menon > Cc: Peter Hurley > Cc: Rafael J. Wysocki > Cc: Ulf Hansson > Cc: Tero Kristo > Signed-off-by: Tony Lindgren Acked-by: Ulf Hansson Kind regards Uffe > --- > > Greg & Peter, I'd like to merge this along with other related fixes > via the ARM SoC tree if no objections, please review and ack if this > look OK to you. > > --- > drivers/tty/serial/8250/8250_omap.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c > index a2c0734..81ff337 100644 > --- a/drivers/tty/serial/8250/8250_omap.c > +++ b/drivers/tty/serial/8250/8250_omap.c > @@ -1235,7 +1235,8 @@ static int omap8250_probe(struct platform_device *pdev) > pm_runtime_put_autosuspend(&pdev->dev); > return 0; > err: > - pm_runtime_put(&pdev->dev); > + pm_runtime_dont_use_autosuspend(&pdev->dev); > + pm_runtime_put_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > return ret; > } > @@ -1244,6 +1245,7 @@ static int omap8250_remove(struct platform_device *pdev) > { > struct omap8250_priv *priv = platform_get_drvdata(pdev); > > + pm_runtime_dont_use_autosuspend(&pdev->dev); > pm_runtime_put_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > serial8250_unregister_port(priv->line); > -- > 2.7.0 >