| Message ID | 1417538845-10867-2-git-send-email-stefan@agner.ch (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Am Dienstag, den 02.12.2014, 17:47 +0100 schrieb Stefan Agner: > Enable IPG clock for sdio interrupts while runtime PM, since this > clock is needed for register access. The need of this clock has been > verified on Vybrid, but this is probably true for i.MX53 and maybe > others. The need for bus access during runtime suspend has been > introduced with be138554a792 ("mmc: sdhci: allow sdio interrupts > while sdhci runtime suspended"). > Am I reading this wrong, or is this commit actually doing something different than what the commit message says? This does _not_ enable the IPG clock during runtime PM, in fact it is disabling it while suspending even with SDIO ints enabled, which is wrong, as no SDIO interrupts will be delivered with this clock disabled. One thing that seems to be wrong with the current code is that the state of sdhci_sdio_irq_enabled could change between a runtime suspend and resume, so to keep the clocks balanced the driver has to remember if it disabled those two clocks in the suspend path and always enable them in that case in the resume path. Regards, Lucas > Signed-off-by: Stefan Agner <stefan@agner.ch> > --- > drivers/mmc/host/sdhci-esdhc-imx.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c > index 587ee0e..b7e9ad1 100644 > --- a/drivers/mmc/host/sdhci-esdhc-imx.c > +++ b/drivers/mmc/host/sdhci-esdhc-imx.c > @@ -1193,10 +1193,10 @@ static int sdhci_esdhc_runtime_suspend(struct device *dev) > > ret = sdhci_runtime_suspend_host(host); > > - if (!sdhci_sdio_irq_enabled(host)) { > + if (!sdhci_sdio_irq_enabled(host)) > clk_disable_unprepare(imx_data->clk_per); > - clk_disable_unprepare(imx_data->clk_ipg); > - } > + > + clk_disable_unprepare(imx_data->clk_ipg); > clk_disable_unprepare(imx_data->clk_ahb); > > return ret; > @@ -1208,10 +1208,10 @@ static int sdhci_esdhc_runtime_resume(struct device *dev) > struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); > struct pltfm_imx_data *imx_data = pltfm_host->priv; > > - if (!sdhci_sdio_irq_enabled(host)) { > + if (!sdhci_sdio_irq_enabled(host)) > clk_prepare_enable(imx_data->clk_per); > - clk_prepare_enable(imx_data->clk_ipg); > - } > + > + clk_prepare_enable(imx_data->clk_ipg); > clk_prepare_enable(imx_data->clk_ahb); > > return sdhci_runtime_resume_host(host);
On 2014-12-03 10:25, Lucas Stach wrote: > Am Dienstag, den 02.12.2014, 17:47 +0100 schrieb Stefan Agner: >> Enable IPG clock for sdio interrupts while runtime PM, since this >> clock is needed for register access. The need of this clock has been >> verified on Vybrid, but this is probably true for i.MX53 and maybe >> others. The need for bus access during runtime suspend has been >> introduced with be138554a792 ("mmc: sdhci: allow sdio interrupts >> while sdhci runtime suspended"). >> > Am I reading this wrong, or is this commit actually doing something > different than what the commit message says? > > This does _not_ enable the IPG clock during runtime PM, in fact it is > disabling it while suspending even with SDIO ints enabled, which is > wrong, as no SDIO interrupts will be delivered with this clock disabled. You are completely right. What I wanted was what is written in the commit message, but I misinterpreted the code! => This patch is invalid. > One thing that seems to be wrong with the current code is that the state > of sdhci_sdio_irq_enabled could change between a runtime suspend and > resume, so to keep the clocks balanced the driver has to remember if it > disabled those two clocks in the suspend path and always enable them in > that case in the resume path. As far as I can see, the only place where that flag changes is in sdhci_enable_sdio_irq. But this function makes sure runtime PM is off while changing that, so I guess it's ok.... -- Stefan > >> Signed-off-by: Stefan Agner <stefan@agner.ch> >> --- >> drivers/mmc/host/sdhci-esdhc-imx.c | 12 ++++++------ >> 1 file changed, 6 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c >> index 587ee0e..b7e9ad1 100644 >> --- a/drivers/mmc/host/sdhci-esdhc-imx.c >> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c >> @@ -1193,10 +1193,10 @@ static int sdhci_esdhc_runtime_suspend(struct device *dev) >> >> ret = sdhci_runtime_suspend_host(host); >> >> - if (!sdhci_sdio_irq_enabled(host)) { >> + if (!sdhci_sdio_irq_enabled(host)) >> clk_disable_unprepare(imx_data->clk_per); >> - clk_disable_unprepare(imx_data->clk_ipg); >> - } >> + >> + clk_disable_unprepare(imx_data->clk_ipg); >> clk_disable_unprepare(imx_data->clk_ahb); >> >> return ret; >> @@ -1208,10 +1208,10 @@ static int sdhci_esdhc_runtime_resume(struct device *dev) >> struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); >> struct pltfm_imx_data *imx_data = pltfm_host->priv; >> >> - if (!sdhci_sdio_irq_enabled(host)) { >> + if (!sdhci_sdio_irq_enabled(host)) >> clk_prepare_enable(imx_data->clk_per); >> - clk_prepare_enable(imx_data->clk_ipg); >> - } >> + >> + clk_prepare_enable(imx_data->clk_ipg); >> clk_prepare_enable(imx_data->clk_ahb); >> >> return sdhci_runtime_resume_host(host);
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index 587ee0e..b7e9ad1 100644 --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -1193,10 +1193,10 @@ static int sdhci_esdhc_runtime_suspend(struct device *dev) ret = sdhci_runtime_suspend_host(host); - if (!sdhci_sdio_irq_enabled(host)) { + if (!sdhci_sdio_irq_enabled(host)) clk_disable_unprepare(imx_data->clk_per); - clk_disable_unprepare(imx_data->clk_ipg); - } + + clk_disable_unprepare(imx_data->clk_ipg); clk_disable_unprepare(imx_data->clk_ahb); return ret; @@ -1208,10 +1208,10 @@ static int sdhci_esdhc_runtime_resume(struct device *dev) struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct pltfm_imx_data *imx_data = pltfm_host->priv; - if (!sdhci_sdio_irq_enabled(host)) { + if (!sdhci_sdio_irq_enabled(host)) clk_prepare_enable(imx_data->clk_per); - clk_prepare_enable(imx_data->clk_ipg); - } + + clk_prepare_enable(imx_data->clk_ipg); clk_prepare_enable(imx_data->clk_ahb); return sdhci_runtime_resume_host(host);
Enable IPG clock for sdio interrupts while runtime PM, since this clock is needed for register access. The need of this clock has been verified on Vybrid, but this is probably true for i.MX53 and maybe others. The need for bus access during runtime suspend has been introduced with be138554a792 ("mmc: sdhci: allow sdio interrupts while sdhci runtime suspended"). Signed-off-by: Stefan Agner <stefan@agner.ch> --- drivers/mmc/host/sdhci-esdhc-imx.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)