On Tue, 16 Jul 2019 at 17:01, Ulrich Hecht <uli+renesas@xxxxxxxx> wrote: > > This fixes a clock imbalance that occurs because the SD clock is handled > by both PM and the hardware driver. > See https://www.spinics.net/lists/linux-mmc/msg44431.html for details. This is a generic problem, when a device are being attached to a genpd and when the genpd has got the ->stop|start() callbacks assigned, as to manage device clocks. Can you try to describe this problem a little bit more in detail, as I think that's important to carry in the change log. > > This patch removes the clock handling from the driver's PM callbacks and runtime PM callbacks and/or system PM callbacks? > turns the clock off after probing. > > Reported-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> > Signed-off-by: Ulrich Hecht <uli+renesas@xxxxxxxx> > --- > drivers/mmc/host/tmio_mmc_core.c | 24 ++++++------------------ > 1 file changed, 6 insertions(+), 18 deletions(-) > > diff --git a/drivers/mmc/host/tmio_mmc_core.c b/drivers/mmc/host/tmio_mmc_core.c > index 31ffcc3..26dcbba 100644 > --- a/drivers/mmc/host/tmio_mmc_core.c > +++ b/drivers/mmc/host/tmio_mmc_core.c > @@ -1260,9 +1260,14 @@ int tmio_mmc_host_probe(struct tmio_mmc_host *_host) > /* See if we also get DMA */ > tmio_mmc_request_dma(_host, pdata); > > - pm_runtime_set_active(&pdev->dev); > +#ifdef CONFIG_PM > + /* PM handles the clock; disable it so it won't be enabled twice. */ > + if (_host->clk_disable) > + _host->clk_disable(_host); The clock managed here, is that the same clock as being managed by genpd's ->stop|start() callbacks? > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_set_autosuspend_delay(&pdev->dev, 50); > pm_runtime_use_autosuspend(&pdev->dev); > +#endif So what happens if you have CONFIG_PM set, but the device doesn't have a genpd attached? I am guessing the driver should handle the clock in such scenario, right? > > ret = mmc_add_host(mmc); > if (ret) > @@ -1302,20 +1307,6 @@ void tmio_mmc_host_remove(struct tmio_mmc_host *host) > EXPORT_SYMBOL_GPL(tmio_mmc_host_remove); > > #ifdef CONFIG_PM > -static int tmio_mmc_clk_enable(struct tmio_mmc_host *host) > -{ > - if (!host->clk_enable) > - return -ENOTSUPP; > - > - return host->clk_enable(host); > -} > - > -static void tmio_mmc_clk_disable(struct tmio_mmc_host *host) > -{ > - if (host->clk_disable) > - host->clk_disable(host); > -} > - > int tmio_mmc_host_runtime_suspend(struct device *dev) > { > struct tmio_mmc_host *host = dev_get_drvdata(dev); > @@ -1325,8 +1316,6 @@ int tmio_mmc_host_runtime_suspend(struct device *dev) > if (host->clk_cache) > host->set_clock(host, 0); > > - tmio_mmc_clk_disable(host); > - > return 0; > } > EXPORT_SYMBOL_GPL(tmio_mmc_host_runtime_suspend); > @@ -1340,7 +1329,6 @@ int tmio_mmc_host_runtime_resume(struct device *dev) > { > struct tmio_mmc_host *host = dev_get_drvdata(dev); > > - tmio_mmc_clk_enable(host); > tmio_mmc_hw_reset(host->mmc); > > if (host->clk_cache) > -- > 2.7.4 > Kind regards Uffe
