On Thu, 2016-04-21 at 19:22 +0800, Jisheng Zhang wrote: > If i2c_dw_probe() fails, we should disable and unprepare the clock, > otherwise the clock enable and prepare is left unbalanced. > > In dw_i2c_plat_remove(), we'd better to not rely on rpm to disable Sorry, didn't notice earlier rpm -> runtime PM > and unprepare the clock since CONFIG_PM may be disabled when > configuring the kernel. So we explicitly disable and unprepare the > clock in dw_i2c_plat_remove() rather than implicitly rely on > pm_runtime_put_sync(). To keep the device usage count balanced, we > call pm_runtime_put_noidle(() to decrease the usage count. (() -> () > > Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxxx> I don't know if Wolfram wants you to send new version, and I dunno if others still have comments, but Patch is in a good shape, but I think we have to carefully check the runtime PM change. > --- > Since v2: > - s/clk/clock > - describe why use pm_runtime_put_noidle() > > Since v1: > - fix commit msg: "not rely on rpm" rather than "rely on rpm" > - call i2c_dw_plat_prepare_clk after pm_rumtime_disable() > > drivers/i2c/busses/i2c-designware-platdrv.c | 16 ++++++++++------ > 1 file changed, 10 insertions(+), 6 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c > b/drivers/i2c/busses/i2c-designware-platdrv.c > index d656657..a771781 100644 > --- a/drivers/i2c/busses/i2c-designware-platdrv.c > +++ b/drivers/i2c/busses/i2c-designware-platdrv.c > @@ -253,8 +253,11 @@ static int dw_i2c_plat_probe(struct > platform_device *pdev) > } > > r = i2c_dw_probe(dev); > - if (r && !dev->pm_runtime_disabled) > - pm_runtime_disable(&pdev->dev); > + if (r) { > + if (!dev->pm_runtime_disabled) > + pm_runtime_disable(&pdev->dev); > + i2c_dw_plat_prepare_clk(dev, false); > + } > > return r; > } > @@ -264,15 +267,16 @@ static int dw_i2c_plat_remove(struct > platform_device *pdev) > struct dw_i2c_dev *dev = platform_get_drvdata(pdev); > > pm_runtime_get_sync(&pdev->dev); > + pm_runtime_dont_use_autosuspend(&pdev->dev); > + if (!dev->pm_runtime_disabled) > + pm_runtime_disable(&pdev->dev); > + pm_runtime_put_noidle(&pdev->dev); > > i2c_del_adapter(&dev->adapter); > > i2c_dw_disable(dev); > > - pm_runtime_dont_use_autosuspend(&pdev->dev); > - pm_runtime_put_sync(&pdev->dev); > - if (!dev->pm_runtime_disabled) > - pm_runtime_disable(&pdev->dev); > + i2c_dw_plat_prepare_clk(dev, false); > > return 0; > } -- Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Intel Finland Oy -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html