From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ulf Hansson Subject: Re: [PATCH 2/7] i2c: omap: Fix PM regression with deferred probe for pm_runtime_reinit Date: Fri, 12 Feb 2016 13:50:37 +0100 Message-ID: References: <1455145370-20301-1-git-send-email-tony@atomide.com> <1455145370-20301-3-git-send-email-tony@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: Received: from mail-yw0-f177.google.com ([209.85.161.177]:35556 "EHLO mail-yw0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752460AbcBLMui (ORCPT ); Fri, 12 Feb 2016 07:50:38 -0500 Received: by mail-yw0-f177.google.com with SMTP id g127so63373173ywf.2 for ; Fri, 12 Feb 2016 04:50:37 -0800 (PST) In-Reply-To: <1455145370-20301-3-git-send-email-tony@atomide.com> Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: Tony Lindgren Cc: linux-omap , "linux-arm-kernel@lists.infradead.org" , "linux-i2c@vger.kernel.org" , Alan Stern , Kevin Hilman , Nishanth Menon , "Rafael J . Wysocki" , Tero Kristo , Wolfram Sang , Greg Kroah-Hartman , linux-mmc , linux-serial@vger.kernel.org, "linux-spi@vger.kernel.org" , Mark Brown , Peter Hurley 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-i2c@vger.kernel.org > Cc: Alan Stern > Cc: Kevin Hilman > Cc: Nishanth Menon > Cc: Rafael J. Wysocki > Cc: Ulf Hansson > Cc: Tero Kristo > Cc: Wolfram Sang > Signed-off-by: Tony Lindgren Acked-by: Ulf Hansson Kind regards Uffe > --- > > Wolfram, 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/i2c/busses/i2c-omap.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c > index 08d26ba..13c4529 100644 > --- a/drivers/i2c/busses/i2c-omap.c > +++ b/drivers/i2c/busses/i2c-omap.c > @@ -1450,7 +1450,8 @@ omap_i2c_probe(struct platform_device *pdev) > > err_unuse_clocks: > omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0); > - pm_runtime_put(omap->dev); > + pm_runtime_dont_use_autosuspend(omap->dev); > + pm_runtime_put_sync(omap->dev); > pm_runtime_disable(&pdev->dev); > err_free_mem: > > @@ -1468,6 +1469,7 @@ static int omap_i2c_remove(struct platform_device *pdev) > return ret; > > omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0); > + pm_runtime_dont_use_autosuspend(&pdev->dev); > pm_runtime_put_sync(&pdev->dev); > pm_runtime_disable(&pdev->dev); > return 0; > -- > 2.7.0 >