On Thu, 5 Sep 2019 at 02:14, Matthias Kaehlcke <m...@chromium.org> wrote: > > On Tue, Sep 03, 2019 at 04:21:58PM +0200, Ulf Hansson wrote: > > In cases when SDIO IRQs have been enabled, runtime suspend is prevented by > > the driver. However, this still means dw_mci_runtime_suspend|resume() gets > > called during system suspend/resume, via pm_runtime_force_suspend|resume(). > > This means during system suspend/resume, the register context of the dw_mmc > > device most likely loses its register context, even in cases when SDIO IRQs > > have been enabled. > > > > To re-enable the SDIO IRQs during system resume, the dw_mmc driver > > currently relies on the mmc core to re-enable the SDIO IRQs when it resumes > > the SDIO card, but this isn't the recommended solution. Instead, it's > > better to deal with this locally in the dw_mmc driver, so let's do that. > > > > Signed-off-by: Ulf Hansson <ulf.hans...@linaro.org> > > --- > > drivers/mmc/host/dw_mmc.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c > > index eea52e2c5a0c..f114710e82b4 100644 > > --- a/drivers/mmc/host/dw_mmc.c > > +++ b/drivers/mmc/host/dw_mmc.c > > @@ -3460,6 +3460,10 @@ int dw_mci_runtime_resume(struct device *dev) > > /* Force setup bus to guarantee available clock output */ > > dw_mci_setup_bus(host->slot, true); > > > > + /* Re-enable SDIO interrupts. */ > > + if (sdio_irq_enabled(host->slot->mmc)) > > + __dw_mci_enable_sdio_irq(host->slot, 1); > > + > > /* Now that slots are all setup, we can enable card detect */ > > dw_mci_enable_cd(host); > > Looks reasonable to me, besides the bikeshedding over > 'sdio_irq_enabled' (in "mmc: core: Add helper function to indicate > if SDIO IRQs is enabled"). > > One thing I wonder is why this change is only needed for dw_mmc and > mtk-sd, but not for others like sunxi_mmc. Any insights for a SDIO > newb?
mtk-sd and dw_mmc is using MMC_CAP2_SDIO_IRQ_NOTHREAD and sdio_signal_irq(). This is also the case for sdhci, but sdhci is already internally dealing restoring SDIO IRQs during system resume. The other host drivers haven't yet converted to MMC_CAP2_SDIO_IRQ_NOTHREAD. I have a series for that, not yet completed and thus not ready to be posted. Once that happens, all host drivers needs to care about re-enabling SDIO IRQs durings system resume as well. For those host that currently doesn't use MMC_CAP2_SDIO_IRQ_NOTHREAD, the core wakes up the sdio_irq_thread from mmc_sdio_resume(), which later will calls the ->enable_sdio_irq(). Perhaps I should add some information about this in the changelog, let me think about it for the next version. Kind regards Uffe
