| Message ID | 1563289264-26432-2-git-send-email-uli+renesas@fpond.eu (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mmc: tmio: remove Gen2+ workaround and fix up | expand |
On Tue, Jul 16, 2019 at 05:01:03PM +0200, Ulrich Hecht 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 patch removes the clock handling from the driver's PM callbacks and > turns the clock off after probing. > > Reported-by: Geert Uytterhoeven <geert+renesas@glider.be> > Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu> Thanks, Uli! Niklas, I'd really like your feedback on this one because you did the PM refactorization lately. I will have a look later, too.
On 2019-07-16 21:05:24 +0200, Wolfram Sang wrote: > On Tue, Jul 16, 2019 at 05:01:03PM +0200, Ulrich Hecht 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 patch removes the clock handling from the driver's PM callbacks and > > turns the clock off after probing. > > > > Reported-by: Geert Uytterhoeven <geert+renesas@glider.be> > > Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu> > > Thanks, Uli! > > Niklas, I'd really like your feedback on this one because you did the PM > refactorization lately. I would like to test this too. Unfortunately I'm on the road and will be back in the office the 23rd so I will have to postpone doing so until then. My initial comment is that this looks good, thanks Ulrich. > > I will have a look later, too. >
On Tue, 16 Jul 2019 at 17:01, Ulrich Hecht <uli+renesas@fpond.eu> 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@glider.be> > Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu> > --- > 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
Hi Ulf, On Thu, Jul 25, 2019 at 3:44 PM Ulf Hansson <ulf.hansson@linaro.org> wrote: > On Tue, 16 Jul 2019 at 17:01, Ulrich Hecht <uli+renesas@fpond.eu> 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@glider.be> > > Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu> > > --- > > 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? That's OK for all SoCs served by renesas_sdhi_internal_dmac.c and renesas_sdhi_sys_dmac.c, as they all have their clock domain described in DT... > I am guessing the driver should handle the clock in such scenario, right? ... but it's not for (non-Renesas) systems served by tmio_mmc.c. Gr{oetje,eeting}s, Geert
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); + 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) @@ -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)
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 patch removes the clock handling from the driver's PM callbacks and turns the clock off after probing. Reported-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu> --- drivers/mmc/host/tmio_mmc_core.c | 24 ++++++------------------ 1 file changed, 6 insertions(+), 18 deletions(-)