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How to confirm XXX_PowerUp/Down of a SDHC Driver? RRS feed

  • Question

  • Hi all,

    I need to know how to confirm XXX_PowerUp/Down of a SDHC Driver. I've looked into PLATFORM\DEVICEEMULATOR\SRC\DRIVERS\SDHC, ARUBABOARD\SRC\DRIVERS\SDHC, PLATFORM\COMMON\SRC\SOC\PXA27X_MS_V1\SDHC. I wonder whether the function SDHCDPowerUpDown must be called by a SDHC driver? That function's definiton says it notifies the bus driver of a power up/down event. In that case, can we say that the SD bus driver can load/unload SDIO child drivers in response to card removal/insertion if only SDHCDPowerUpDown is called by host controller? If XXX_PowerUp/Down of SDHC driver does not include SDHCDPowerUpDown call, is it a lack of driver?

    Thanks in advance for your helps and clarificaitons

    Best regards

    Tuesday, November 23, 2010 1:31 PM

All replies

  • xxx_PowerUp() and xxx_PowerDown() are used by the Power Manager when system is suspend (xxx_PowerDown) or resumed (xxx_PowerUp).

    They are optional, if they are not present, they are simply not called ;-)

     

    Hope this helps

    Fabrice

    Tuesday, November 23, 2010 2:38 PM
  • Thanks for your reply.

    SDHC driver implements XXX_PowerUp and XXX_PowerDown but I'm trying to find out whether there is a lack of it's implementation. So I asked that if XXX_PowerUp/Down of SDHC driver does not include SDHCDPowerUpDown call, is it a lack of SDHC's driver?

    I want to ask one more question. Does SDBus driver load or unload the SDIO client drivers in response to which function of SDHC's driver?

    Tuesday, November 23, 2010 2:52 PM
  • You must have a real problem that you are trying to solve.  You seem to be asking about some solution that you think is appropriate, but may not be.  So telling us about your real problem may get you some assistance quicker.

    For one thing, XXX_PowerUp/Down have nothing to do with card insertion/removal.  The have to do with suspend/resume.


    Bruce Eitman (eMVP)
    Senior Engineer
    Bruce.Eitman AT Eurotech DOT com
    My BLOG http://geekswithblogs.net/bruceeitman

    Eurotech Inc.
    www.Eurotech.com
    Tuesday, November 23, 2010 3:42 PM
    Moderator
  • You're right. I need that the capabilities of loading/unloading (at the state of insertion/removal) SDIO client drivers to give to an application in order to overcome loading problems encountered betimes. I know that SD bus driver is responsible for loading/unloding SDIO client drivers. I thought the loading/unloading command can be given to SD bus driver through SDHC driver. So I've decided to change the XXX_IOControl of SDHC driver (current SDHC driver has empty XXX_IOControl implementation.) For example the functions SDHCDPowerUpDown, SDHCDIndicateBusRequestComplete, SDHCDIndicateSlotStateChange can be used for notifying the SD bus driver into SDHC driver. But I don't know SDBus driver loads or unloads the SDIO client drivers in response to which function of SDHC's driver? Does a similiar function exist to do it? Thanks a lot for helps in advance
    Tuesday, November 23, 2010 6:26 PM
  • Wrong approach, I say.  If you have some sort of loading problems: FIX THEM.  If you then want to add for some debugging purposes the ability to unload a client driver, you can do that, I suppose, but you're just wasting your time right now by not addressing the actual problem that you you need to fix.

    Paul T.

    Wednesday, November 24, 2010 2:56 PM