From mboxrd@z Thu Jan 1 00:00:00 1970 From: tony@atomide.com (Tony Lindgren) Date: Wed, 10 Feb 2016 15:02:47 -0800 Subject: [PATCH 4/7] serial: 8250_omap: Fix PM regression with deferred probe for pm_runtime_reinit In-Reply-To: <1455145370-20301-1-git-send-email-tony@atomide.com> References: <1455145370-20301-1-git-send-email-tony@atomide.com> Message-ID: <1455145370-20301-5-git-send-email-tony@atomide.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 --- 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