On Wed, 25 Aug 2021 at 16:34, Yann Gautier <yann.gautier@xxxxxxxxxxx> wrote: > > Hi, > > In drivers/mmc/host/mmci.c, MMC_PM_KEEP_POWER is unconditionally enabled. > This prevents correct low-power sequence on STM32MP157C-DK2 board which > embeds a Wifi chip brcm,bcm4329-fmac (this wifi part has not yet been > sent upstream). Exactly why doesn't this work with the STM32MP157C-DK2 board? > > This MMC_PM_KEEP_POWER can be taken from DT with the property > keep-power-in-suspend. This is what is done for other MMC drivers. The DT property is what should have been used for mmci as well. > > I wonder what should be the best solution for this. > > 1) Remove MMC_PM_KEEP_POWER from the driver, and modify all SoC device > tree files embedding a arm,pl18x with adding keep-power-in-suspend; > property (except stm32mp151.dtsi file). > This can be easy to do (~10 files to modify). But that could be more > board dependent, if an SDIO chip is plugged on this MMC IP. > And the name keep-power-in-suspend can be misleading as it only applies > to SDIO. > > 2) Remove MMC_PM_KEEP_POWER from the driver, and modify board DT files > with the property. This could be a difficult task to find all those > boards. And this should be applied only for SDIO configs. > > 3) Just modify the driver to apply this capability for all MMCI chips > but STM32. This could be done in the dedicated file, in > sdmmc_variant_init() function. But some boards based on STM32MP15 chip > might want to keep this capability. I would suggest option 3). As a matter of fact, we also allow MMC_PM_KEEP_POWER to become set when parsing the DTB via calling mmc_of_parse(). So just changing the default value (don't set MMC_PM_KEEP_POWER) for the stm32 variant, would do the trick I think. Kind regards Uffe
