On 17 September 2014 11:11, micky <micky_ching@xxxxxxxxxxxxxx> wrote: > On 09/17/2014 02:01 AM, Ulf Hansson wrote: >> >> On 12 September 2014 03:39, <micky_ching@xxxxxxxxxxxxxx> wrote: >>> >>> From: Roger Tseng <rogerable@xxxxxxxxxxx> >>> >>> Some platform have both UEFI driver and MFD/mmc driver, if entering >>> linux while card in the slot, the card power is already on, and rtsx-mmc >>> driver have no chance to make card power off. This will lead UHSI card >>> failed to enter UHSI mode. >>> >>> It is hard to control the UEFI driver leaving state, so we power off the >>> card power during probe. >>> >>> Signed-off-by: Roger Tseng <rogerable@xxxxxxxxxxx> >>> Signed-off-by: Micky Ching <micky_ching@xxxxxxxxxxxxxx> >>> --- >>> drivers/mmc/host/rtsx_pci_sdmmc.c | 7 ++++++- >>> 1 file changed, 6 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c >>> b/drivers/mmc/host/rtsx_pci_sdmmc.c >>> index dfde4a2..57b0796 100644 >>> --- a/drivers/mmc/host/rtsx_pci_sdmmc.c >>> +++ b/drivers/mmc/host/rtsx_pci_sdmmc.c >>> @@ -1341,8 +1341,13 @@ static int rtsx_pci_sdmmc_drv_probe(struct >>> platform_device *pdev) >>> host->pcr = pcr; >>> host->mmc = mmc; >>> host->pdev = pdev; >>> - host->power_state = SDMMC_POWER_OFF; >>> INIT_WORK(&host->work, sd_request); >>> + sd_power_off(host); >>> + /* >>> + * ref: SD spec 3.01: 6.4.1.2 Power On or Power Cycle >>> + */ >>> + usleep_range(1000, 2000); >>> + >> >> This won't work in cases were you power off eMMC cards, unless you can >> do a full power cycle - cut both VCC and VCCQ. Can you? > > Hi Uffe, > > VCCQ will poweroff at the same time. In that case, don't forget to enable MMC_CAP2_FULL_PWR_CYCLE. > > if MMC_CAP2_NO_PRESCAN_POWERUP enable, will call mmc_power_off() at start, > then it will check ios.power_mode, but the state is MMC_POWER_OFF and just > return. Uhh, that's right! So, I wonder why we invokes mmc_power_off() from that path at all. Hmm, I think we should change the behavior in mmc_start_host(), like below: 1) Add a "MMC_POWER_UNDEFINED" state which is what the power state should be assigned to at allocation. 2 ) From mmc_start_host(), invoke mmc_power_off() when MMC_CAP2_NO_PRESCAN_POWERUP and MMC_CAP2_FULL_PWR_CYCLE is set. Would that work? Kind regards Uffe > Best Regards. > micky. > >> There are also another option you might want to use, >> MMC_CAP2_NO_PRESCAN_POWERUP. But again, it must only be used for those >> hosts that you are able to do a full power cycle for. >> >> Kind regards >> Uffe >> >>> platform_set_drvdata(pdev, host); >>> pcr->slots[RTSX_SD_CARD].p_dev = pdev; >>> pcr->slots[RTSX_SD_CARD].card_event = rtsx_pci_sdmmc_card_event; >>> -- >>> 1.7.9.5 >>> >> . >> > _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
