From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthias Kaehlcke Subject: Re: [PATCH 02/11] mmc: dw_mmc: Re-store SDIO IRQs mask at system resume Date: Wed, 4 Sep 2019 17:14:22 -0700 Message-ID: <20190905001422.GH70797@google.com> References: <20190903142207.5825-1-ulf.hansson@linaro.org> <20190903142207.5825-3-ulf.hansson@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <20190903142207.5825-3-ulf.hansson@linaro.org> Sender: linux-kernel-owner@vger.kernel.org To: Ulf Hansson Cc: linux-mmc@vger.kernel.org, Adrian Hunter , Douglas Anderson , Shawn Lin , Jaehoon Chung , Yong Mao , Chaotian Jing , linux-kernel@vger.kernel.org List-Id: linux-mmc@vger.kernel.org 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 > --- > 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?