On Mon, 14 Mar 2022 at 17:52, Yann Gautier <yann.gautier@xxxxxxxxxxx> wrote: > > On 3/14/22 17:18, Ulf Hansson wrote: > > On Mon, 14 Mar 2022 at 15:34, Yann Gautier <yann.gautier@xxxxxxxxxxx> wrote: > >> > >> On 3/14/22 14:03, Ulf Hansson wrote: > >>> On Mon, 14 Mar 2022 at 13:56, Yann Gautier <yann.gautier@xxxxxxxxxxx> wrote: > >>>> > >>>> Add a disable_keep_power field in variant_data struct. The > >>>> MMC_PM_KEEP_POWER flag will be enabled if disable_keep_power is not set. > >>>> It is only set to true for stm32_sdmmc variants. > >>>> > >>>> The issue was seen on STM32MP157C-DK2 board, which embeds a wifi chip. > >>>> It doesn't correctly support low power on this board. The Wifi chip > >>>> awaits an always-on regulator, but it was connected to v3v3 which is off > >>>> in low-power sequence. MMC_PM_KEEP_POWER should then be disabled. > >>> > >>> Just to make sure I get this correct. > >>> > >>> Why can't the regulator stay on during system suspend? The point is, > >>> we don't need an always on regulator to cope with this. > >>> > >>> Kind regards > >>> Uffe > >> > >> Hi Ulf, > >> > >> This v3v3 regulator powers most of the devices on this board. So we need > >> to switch it off to gain power in suspend mode. > > > > I see. Thanks for sharing that information. > > > > The MMC_PM_KEEP_POWER flag is there to describe what is supported by > > the platform/host. It doesn't mean that the card *must* stay powered > > on during system suspend. Instead that depends on whether system > > wakeup for the SDIO/WiFi is supported too - and if that is enabled by > > userspace. If not, the regulator will be turned off for the SDIO card > > during system suspend. > > > > Assuming the regulator is implemented as a proper regulator and can > > remain on during system suspend, the right thing would be to keep the > > MMC_PM_KEEP_POWER flag around. > > > > Kind regards > > Uffe > > > > OK, but in the wifi driver we use on this platform (brcmfmac), the > suspend/resume functions (brcmf_ops_sdio_suspend/brcmf_ops_sdio_resume) > use the flag to check regu was off, and then call probe function during > resume, to re-init Wifi chip and reload its firmware. I had a closer look at the brcmfmac driver, thanks for the pointers. In my opinion, I think we should change the brcmfmac driver, so it decides to power off the SDIO card, unless the WiFi chip is configured to serve us with system wakeups. I can send a patch for brcmfmac that we can try, unless you want to send it yourself? > > > Best regards, > Yann Kind regards Uffe > > >> > >> > >> Yann > >> > >>> > >>>> > >>>> The flag can still be enabled through DT property: > >>>> keep-power-in-suspend. > >>>> > >>>> Signed-off-by: Yann Gautier <yann.gautier@xxxxxxxxxxx> > >>>> --- > >>>> Update in v2: > >>>> Reword commit message to better explain the issue. > >>>> > >>>> Resend the patch alone. It was previoulsy in a series [1] for which the > >>>> other patches will be reworked. > >>>> > >>>> [1] https://lore.kernel.org/lkml/20220304135134.47827-1-yann.gautier@xxxxxxxxxxx/ > >>>> > >>>> drivers/mmc/host/mmci.c | 5 ++++- > >>>> drivers/mmc/host/mmci.h | 1 + > >>>> 2 files changed, 5 insertions(+), 1 deletion(-) > >>>> > >>>> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c > >>>> index 45b8608c935c..0e2f2f5d6a52 100644 > >>>> --- a/drivers/mmc/host/mmci.c > >>>> +++ b/drivers/mmc/host/mmci.c > >>>> @@ -274,6 +274,7 @@ static struct variant_data variant_stm32_sdmmc = { > >>>> .busy_detect = true, > >>>> .busy_detect_flag = MCI_STM32_BUSYD0, > >>>> .busy_detect_mask = MCI_STM32_BUSYD0ENDMASK, > >>>> + .disable_keep_power = true, > >>>> .init = sdmmc_variant_init, > >>>> }; > >>>> > >>>> @@ -301,6 +302,7 @@ static struct variant_data variant_stm32_sdmmcv2 = { > >>>> .busy_detect = true, > >>>> .busy_detect_flag = MCI_STM32_BUSYD0, > >>>> .busy_detect_mask = MCI_STM32_BUSYD0ENDMASK, > >>>> + .disable_keep_power = true, > >>>> .init = sdmmc_variant_init, > >>>> }; > >>>> > >>>> @@ -2172,7 +2174,8 @@ static int mmci_probe(struct amba_device *dev, > >>>> host->stop_abort.flags = MMC_RSP_R1B | MMC_CMD_AC; > >>>> > >>>> /* We support these PM capabilities. */ > >>>> - mmc->pm_caps |= MMC_PM_KEEP_POWER; > >>>> + if (!variant->disable_keep_power) > >>>> + mmc->pm_caps |= MMC_PM_KEEP_POWER; > >>>> > >>>> /* > >>>> * We can do SGIO > >>>> diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h > >>>> index e1a9b96a3396..2cad1ef9766a 100644 > >>>> --- a/drivers/mmc/host/mmci.h > >>>> +++ b/drivers/mmc/host/mmci.h > >>>> @@ -361,6 +361,7 @@ struct variant_data { > >>>> u32 opendrain; > >>>> u8 dma_lli:1; > >>>> u32 stm32_idmabsize_mask; > >>>> + u8 disable_keep_power:1; > >>>> void (*init)(struct mmci_host *host); > >>>> }; > >>>> > >>>> -- > >>>> 2.25.1 > >>>> > >> >
