On Tue, 15 Mar 2022 at 11:08, Yann Gautier <yann.gautier@xxxxxxxxxxx> wrote: > > On 3/15/22 10:07, Ulf Hansson wrote: > > 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? > > > > Hi Ulf, > If you already have an idea of the patch in the brcmfmac driver, can you > propose something? Sure, I will post a patch as soon as I can. > We'll be able to test it at our side. Great, I will keep you posted! [...] Kind regards Uffe
