Re: [PATCH 1/1] MdeModulePkg/SdMmcPciHcDxe: Fix bus timing switch sequence

["Wu, Hao A" <hao.a.wu@intel.com>]

> -----Original Message-----
> From: Albecki, Mateusz
> Sent: Monday, September 23, 2019 4:37 PM
> To: devel@edk2.groups.io
> Cc: Albecki, Mateusz; Wu, Hao A; Marcin Wojtas
> Subject: [PATCH 1/1] MdeModulePkg/SdMmcPciHcDxe: Fix bus timing
> switch sequence
> 
> SD specification recommends switching card bus timing before
> switching bus timing in controller. Emmc driver used to do
> this switch other way around. This commit adds controller
> timing switch in EmmcSwitchBusTiming function to enforce this
> order and removes all controller timing programing from
> EmmcSwitchToXXX functions.


Hello Mateusz,

I think the changes in the patch look good.

Could you help to address the below things:

1. The 'Private' local variable is no longer being used by below functions:
EmmcSwitchToHighSpeed()
EmmcSwitchToHS200()
EmmcSwitchToHS400()

The GCC compiler seems not happy with it, could you help to resolve it?

2. I have submitted a Bugzilla tracker for this issue at:
https://bugzilla.tianocore.org/show_bug.cgi?id=2218

Could you help to add this information in the commit log message?

3. For the removal of bus clock stopping codes in EmmcSwitchToHS200(), could
you split them into another separate patch? I think they are not directly
related with the bus speed mode changing sequence.

4. I have performed the below tests on the eMMC device on my side, for
different eMMC bus modes:
HS400 (good)
HS200 (good)
High Speed DDR (good)
High Speed SDR (good)
Legacy MMC (NOT good)

For the Legacy MMC mode case, the error comes from the EmmcSwitchToHighSpeed()
function returning EFI_INVALID_PARAMETER for bus mode 'SdMmcMmcLegacy'. I think
for the EmmcSetBusMode() function, the below updates can be made:

  if (BusMode.BusTiming == SdMmcMmcHs400) {
    Status = EmmcSwitchToHS400 (PciIo, PassThru, Slot, Rca, &BusMode);
  } else if (BusMode.BusTiming == SdMmcMmcHs200) {
    Status = EmmcSwitchToHS200 (PciIo, PassThru, Slot, Rca, &BusMode);
  } else {  <== should be updated to:
  } else if (BusMode.BusTiming == SdMmcMmcHsSdr || BusMode.BusTiming == SdMmcMmcHsDdr) {
    Status = EmmcSwitchToHighSpeed (PciIo, PassThru, Slot, Rca, &BusMode);
  }

think for the Legacy MMC mode, no additional bus mode switch is needed. If
you agree with this, could you help to add another patch to change the above
logic (also the debug message after the above-shown code)?

Best  Regards,
Hao Wu


> 
> Signed-off-by: Mateusz Albecki <mateusz.albecki@intel.com>
> Cc: Hao A Wu <hao.a.wu@intel.com>
> Cc: Marcin Wojtas <mw@semihalf.com>
> ---
>  MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/EmmcDevice.c | 79 +++++++-------
> -----------
>  1 file changed, 20 insertions(+), 59 deletions(-)
> 
> diff --git a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/EmmcDevice.c
> b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/EmmcDevice.c
> index 3f4a8e5413..06ee1208be 100644
> --- a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/EmmcDevice.c
> +++ b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/EmmcDevice.c
> @@ -671,6 +671,7 @@ EmmcSwitchBusTiming (
>    UINT8                     CmdSet;
>    UINT32                    DevStatus;
>    SD_MMC_HC_PRIVATE_DATA    *Private;
> +  UINT8                     HostCtrl1;
> 
>    Private = SD_MMC_HC_PRIVATE_FROM_THIS (PassThru);
>    //
> @@ -704,6 +705,25 @@ EmmcSwitchBusTiming (
>      return Status;
>    }
> 
> +  if (BusTiming == SdMmcMmcHsSdr || BusTiming == SdMmcMmcHsDdr) {
> +    HostCtrl1 = BIT2;
> +    Status = SdMmcHcOrMmio (PciIo, Slot, SD_MMC_HC_HOST_CTRL1, sizeof
> (HostCtrl1), &HostCtrl1);
> +    if (EFI_ERROR (Status)) {
> +      return Status;
> +    }
> +  } else {
> +    HostCtrl1 = (UINT8)~BIT2;
> +    Status = SdMmcHcAndMmio (PciIo, Slot, SD_MMC_HC_HOST_CTRL1,
> sizeof (HostCtrl1), &HostCtrl1);
> +    if (EFI_ERROR (Status)) {
> +      return Status;
> +    }
> +  }
> +
> +  Status = SdMmcHcUhsSignaling (Private->ControllerHandle, PciIo, Slot,
> BusTiming);
> +  if (EFI_ERROR (Status)) {
> +    return Status;
> +  }
> +
>    //
>    // Convert the clock freq unit from MHz to KHz.
>    //
> @@ -772,7 +792,6 @@ EmmcSwitchToHighSpeed (
>    )
>  {
>    EFI_STATUS              Status;
> -  UINT8                   HostCtrl1;
>    SD_MMC_HC_PRIVATE_DATA  *Private;
>    BOOLEAN                 IsDdr;
> 
> @@ -794,20 +813,6 @@ EmmcSwitchToHighSpeed (
>      return Status;
>    }
> 
> -  //
> -  // Set to High Speed timing
> -  //
> -  HostCtrl1 = BIT2;
> -  Status = SdMmcHcOrMmio (PciIo, Slot, SD_MMC_HC_HOST_CTRL1, sizeof
> (HostCtrl1), &HostCtrl1);
> -  if (EFI_ERROR (Status)) {
> -    return Status;
> -  }
> -
> -  Status = SdMmcHcUhsSignaling (Private->ControllerHandle, PciIo, Slot,
> BusMode->BusTiming);
> -  if (EFI_ERROR (Status)) {
> -    return Status;
> -  }
> -
>    return EmmcSwitchBusTiming (PciIo, PassThru, Slot, Rca, BusMode-
> >DriverStrength, BusMode->BusTiming, BusMode->ClockFreq);
>  }
> 
> @@ -837,7 +842,6 @@ EmmcSwitchToHS200 (
>    )
>  {
>    EFI_STATUS               Status;
> -  UINT16                   ClockCtrl;
>    SD_MMC_HC_PRIVATE_DATA  *Private;
> 
>    Private = SD_MMC_HC_PRIVATE_FROM_THIS (PassThru);
> @@ -851,39 +855,6 @@ EmmcSwitchToHS200 (
>    if (EFI_ERROR (Status)) {
>      return Status;
>    }
> -  //
> -  // Stop bus clock at first
> -  //
> -  Status = SdMmcHcStopClock (PciIo, Slot);
> -  if (EFI_ERROR (Status)) {
> -    return Status;
> -  }
> -
> -  Status = SdMmcHcUhsSignaling (Private->ControllerHandle, PciIo, Slot,
> BusMode->BusTiming);
> -  if (EFI_ERROR (Status)) {
> -    return Status;
> -  }
> -
> -  //
> -  // Wait Internal Clock Stable in the Clock Control register to be 1 before
> set SD Clock Enable bit
> -  //
> -  Status = SdMmcHcWaitMmioSet (
> -             PciIo,
> -             Slot,
> -             SD_MMC_HC_CLOCK_CTRL,
> -             sizeof (ClockCtrl),
> -             BIT1,
> -             BIT1,
> -             SD_MMC_HC_GENERIC_TIMEOUT
> -             );
> -  if (EFI_ERROR (Status)) {
> -    return Status;
> -  }
> -  //
> -  // Set SD Clock Enable in the Clock Control register to 1
> -  //
> -  ClockCtrl = BIT2;
> -  Status = SdMmcHcOrMmio (PciIo, Slot, SD_MMC_HC_CLOCK_CTRL, sizeof
> (ClockCtrl), &ClockCtrl);
> 
>    Status = EmmcSwitchBusTiming (PciIo, PassThru, Slot, Rca, BusMode-
> >DriverStrength, BusMode->BusTiming, BusMode->ClockFreq);
>    if (EFI_ERROR (Status)) {
> @@ -945,11 +916,6 @@ EmmcSwitchToHS400 (
>    // Set to High Speed timing and set the clock frequency to a value less than
> or equal to 52MHz.
>    // This step is necessary to be able to switch Bus into 8 bit DDR mode
> which is unsupported in HS200.
>    //
> -  Status = SdMmcHcUhsSignaling (Private->ControllerHandle, PciIo, Slot,
> SdMmcMmcHsSdr);
> -  if (EFI_ERROR (Status)) {
> -    return Status;
> -  }
> -
>    HsFreq = BusMode->ClockFreq < 52 ? BusMode->ClockFreq : 52;
>    Status = EmmcSwitchBusTiming (PciIo, PassThru, Slot, Rca, BusMode-
> >DriverStrength, SdMmcMmcHsSdr, HsFreq);
>    if (EFI_ERROR (Status)) {
> @@ -961,11 +927,6 @@ EmmcSwitchToHS400 (
>      return Status;
>    }
> 
> -  Status = SdMmcHcUhsSignaling (Private->ControllerHandle, PciIo, Slot,
> BusMode->BusTiming);
> -  if (EFI_ERROR (Status)) {
> -    return Status;
> -  }
> -
>    return EmmcSwitchBusTiming (PciIo, PassThru, Slot, Rca, BusMode-
> >DriverStrength, BusMode->BusTiming, BusMode->ClockFreq);
>  }
> 
> --
> 2.14.1.windows.1