| Message ID | 1564589857-17720-2-git-send-email-uli+renesas@fpond.eu (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
| Series | mmc: tmio: remove Gen2+ workaround and fix up | expand |
On Wed, 31 Jul 2019 at 18:17, Ulrich Hecht <uli+renesas@fpond.eu> wrote: > > This fixes a clock imbalance that occurs on Renesas systems because the SD > clock is handled by both runtime PM and the hardware driver. After a > suspend/resume cycle both enable the same clock, resulting in an enable > count of 2 even if the clock is only used by one device. > > See https://www.spinics.net/lists/linux-mmc/msg44431.html for details. > > This patch removes the clock handling from the driver's runtime PM > callbacks and turns the clock off after probing if the device has a power > domain attached. > > Reported-by: Geert Uytterhoeven <geert+renesas@glider.be> > Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu> > Tested-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> > --- > drivers/mmc/host/tmio_mmc_core.c | 14 +++++++++++--- > 1 file changed, 11 insertions(+), 3 deletions(-) > > diff --git a/drivers/mmc/host/tmio_mmc_core.c b/drivers/mmc/host/tmio_mmc_core.c > index 31ffcc3..733ff96 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 && pdev->dev.pm_domain) Hmm. This seems to work for most cases of yours, but it's fragile, because how do you know that the pm_domain above is managing the clock? You don't. > + _host->clk_disable(_host); > + pm_runtime_get_sync(&pdev->dev); > pm_runtime_set_autosuspend_delay(&pdev->dev, 50); > pm_runtime_use_autosuspend(&pdev->dev); > +#endif > > ret = mmc_add_host(mmc); > if (ret) > @@ -1325,7 +1330,8 @@ int tmio_mmc_host_runtime_suspend(struct device *dev) > if (host->clk_cache) > host->set_clock(host, 0); > > - tmio_mmc_clk_disable(host); > + if (!dev->pm_domain) > + tmio_mmc_clk_disable(host); > > return 0; > } > @@ -1340,7 +1346,9 @@ int tmio_mmc_host_runtime_resume(struct device *dev) > { > struct tmio_mmc_host *host = dev_get_drvdata(dev); > > - tmio_mmc_clk_enable(host); > + if (!dev->pm_domain) > + tmio_mmc_clk_enable(host); > + > tmio_mmc_hw_reset(host->mmc); > > if (host->clk_cache) > -- > 2.7.4 > I am going to think a bit more about this, but at this point, my gut-feeling is that may need to add some helper functions to let genpd and/or the pm_clk framework, to share some internal information with drivers. Kind regards Uffe
Hi Ulf, > > +#ifdef CONFIG_PM > > + /* PM handles the clock; disable it so it won't be enabled twice. */ > > + if (_host->clk_disable && pdev->dev.pm_domain) > > Hmm. > > This seems to work for most cases of yours, but it's fragile, because > how do you know that the pm_domain above is managing the clock? You > don't. > ... > I am going to think a bit more about this, but at this point, my > gut-feeling is that may need to add some helper functions to let genpd > and/or the pm_clk framework, to share some internal information with > drivers. Any outcome of this? Do you want to do it? Kind regards, Wolfram
On Thu, 22 Aug 2019 at 08:35, Wolfram Sang <wsa@the-dreams.de> wrote: > > Hi Ulf, > > > > +#ifdef CONFIG_PM > > > + /* PM handles the clock; disable it so it won't be enabled twice. */ > > > + if (_host->clk_disable && pdev->dev.pm_domain) > > > > Hmm. > > > > This seems to work for most cases of yours, but it's fragile, because > > how do you know that the pm_domain above is managing the clock? You > > don't. > > > > ... > > > I am going to think a bit more about this, but at this point, my > > gut-feeling is that may need to add some helper functions to let genpd > > and/or the pm_clk framework, to share some internal information with > > drivers. > > Any outcome of this? Do you want to do it? Sorry for delay, it's been vacation period. I have some ideas that we can try out, just not yet being formalize them in code. I need to catch up a little bit more on mmc reviews, so unless this is urgent, I can offer my help and post something soonish. Is this fine by you? Kind regards Uffe
Hi Ulf, > I need to catch up a little bit more on mmc reviews, so unless this is > urgent, I can offer my help and post something soonish. > > Is this fine by you? Yep, totally. Hope you had a great vacation! Just wanted ask if you are happy hacking on this or if we could help here somehow. Not urgent, we will wait. Thanks, Wolfram
diff --git a/drivers/mmc/host/tmio_mmc_core.c b/drivers/mmc/host/tmio_mmc_core.c index 31ffcc3..733ff96 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 && pdev->dev.pm_domain) + _host->clk_disable(_host); + pm_runtime_get_sync(&pdev->dev); pm_runtime_set_autosuspend_delay(&pdev->dev, 50); pm_runtime_use_autosuspend(&pdev->dev); +#endif ret = mmc_add_host(mmc); if (ret) @@ -1325,7 +1330,8 @@ int tmio_mmc_host_runtime_suspend(struct device *dev) if (host->clk_cache) host->set_clock(host, 0); - tmio_mmc_clk_disable(host); + if (!dev->pm_domain) + tmio_mmc_clk_disable(host); return 0; } @@ -1340,7 +1346,9 @@ int tmio_mmc_host_runtime_resume(struct device *dev) { struct tmio_mmc_host *host = dev_get_drvdata(dev); - tmio_mmc_clk_enable(host); + if (!dev->pm_domain) + tmio_mmc_clk_enable(host); + tmio_mmc_hw_reset(host->mmc); if (host->clk_cache)