Re: [PATCH edk2-platforms] Silicon/Socionext/SynQuacer: add configurable eMMC support

[Leif Lindholm <leif.lindholm@linaro.org>]

On Tue, Jan 30, 2018 at 11:14:31AM +0000, Ard Biesheuvel wrote:
> On 30 January 2018 at 11:00, Leif Lindholm <leif.lindholm@linaro.org> wrote:
> > On Tue, Jan 30, 2018 at 10:32:40AM +0000, Ard Biesheuvel wrote:
> >> Implement support for the SynQuacer eMMC controller. This involves an
> >> implementation of the SD/MMC override protocol to handle a couple of
> >> quirks that would otherwise prevent this IP from being driven by the
> >> generic SDHCI driver.
> >>
> >> Also, add a HII page to the PlatformDxe driver that allows eMMC support
> >> to be enabled, and wire it up for both DeveloperBox and EVB.
> >>
> >> Contributed-under: TianoCore Contribution Agreement 1.1
> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> >> ---
> >> Now that the core support for the SD/MMC override protocol is finally
> >> merged, resubmit this again. I dropped Leif's R-b given that I have
> >> now added DeveloperBox, as well as a HII option to enable eMMC.
> >
> > Couple of minor comments/suggestions below and a question.
> >
> >>  Platform/Socionext/DeveloperBox/DeveloperBox.dsc                                    |   8 +
> >>  Platform/Socionext/DeveloperBox/DeveloperBox.fdf                                    |   7 +
> >>  Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.dsc                        |   8 +
> >>  Platform/Socionext/SynQuacerEvalBoard/SynQuacerEvalBoard.fdf                        |   7 +
> >>  Silicon/Socionext/SynQuacer/DeviceTree/SynQuacer.dtsi                               |   1 -
> >>  Silicon/Socionext/SynQuacer/DeviceTree/SynQuacerEvalBoard.dts                       |   4 -
> >>  Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/Emmc.c                              | 203 ++++++++++++++++++++
> >>  Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/PlatformDxe.c                       |   5 +
> >>  Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/PlatformDxe.h                       |   9 +
> >>  Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/PlatformDxe.inf                     |   4 +
> >>  Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/PlatformDxeHii.uni                  |   6 +
> >>  Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/PlatformDxeHii.vfr                  |   8 +
> >>  Silicon/Socionext/SynQuacer/Include/Platform/VarStore.h                             |   6 +-
> >>  Silicon/Socionext/SynQuacer/Library/SynQuacerDtbLoaderLib/SynQuacerDtbLoaderLib.c   |  23 ++-
> >>  Silicon/Socionext/SynQuacer/Library/SynQuacerDtbLoaderLib/SynQuacerDtbLoaderLib.inf |   1 +
> >>  15 files changed, 287 insertions(+), 13 deletions(-)
> >>
> >
> >> +/**
> >> +
> >> +  Override function for SDHCI capability bits
> >> +
> >> +  @param[in]      PassThru              A pointer to the
> >> +                                        EFI_SD_MMC_PASS_THRU_PROTOCOL instance.
> >> +  @param[in]      ControllerHandle      The EFI_HANDLE of the controller.
> >> +  @param[in]      Slot                  The 0 based slot index.
> >> +  @param[in,out]  SdMmcHcSlotCapability The SDHCI capability structure.
> >> +
> >> +  @retval EFI_SUCCESS           The override function completed successfully.
> >> +  @retval EFI_NOT_FOUND         The specified controller or slot does not exist.
> >> +  @retval EFI_INVALID_PARAMETER SdMmcHcSlotCapability is NULL
> >> +
> >> +**/
> >> +STATIC
> >> +EFI_STATUS
> >> +EFIAPI
> >> +SynQuacerSdMmcCapability (
> >> +  IN      EFI_HANDLE                      ControllerHandle,
> >> +  IN      UINT8                           Slot,
> >> +  IN  OUT VOID                            *SdMmcHcSlotCapability
> >> +  )
> >> +{
> >> +  UINT64 Capability;
> >> +
> >> +  if (ControllerHandle != mSdMmcControllerHandle || Slot != 0) {
> >
> > This test pattern repeats below, does it suggest a macro?
> >
> 
> I don't see how that would clear things up tbh, and the pattern occurs
> only twice
> 
> #define IS_OUR_QUIRKY_SDMMC_CONTROLLER(Handle, Slot) \
>   ((Handle) == mSdMmcControllerHandle && (Slot) == 0)
> 
> if (!IS_OUR_QUIRKY_SDMMC_CONTROLLER(ControllerHandle, Slot) {
>   return EFI_SUCCESS;
> }
> 
> I can change it if you want, or add a comment if the condition is not
> self-explanatory enough.

It's just an awful lot of logical operations on a single line.
'ControllerHandle != mSdMmcControllerHandle' is reasonably easy to
figure out, but '|| Slot != 0' looks a bit random there.

A comment would be sufficient.

Another option would be to reduce the number of logical operations by
two by doing
  if (ControllerHandle == mSdMmcControllerHandle && Slot == 0) {
and doing the body inside the if-statement.

That's a bit uglier in the next function, but I would expect it
follows the paradigm of "handle most likely case first"?

> >> diff --git a/Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/PlatformDxeHii.uni b/Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/PlatformDxeHii.uni
> >> index b274d12ed2c6..2eca8bbba8c3 100644
> >> --- a/Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/PlatformDxeHii.uni
> >> +++ b/Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/PlatformDxeHii.uni
> >> @@ -27,3 +27,9 @@
> >>
> >>  #string STR_PCIE_MAX_SPEED_UNLIMITED   #language en-US "Unlimited"
> >>  #string STR_PCIE_MAX_SPEED_GEN1        #language en-US "Gen1 (2.5 GT/s)"
> >> +
> >> +#string STR_EMMC_ENABLE_PROMPT         #language en-US "Enable on-board eMMC"
> >> +#string STR_EMMC_ENABLE_HELP           #language en-US "Enable the on-board eMMC for booting and for use by the OS."
> >> +
> >> +#string STR_EMMC_DISABLED              #language en-US "Disabled"
> >> +#string STR_EMMC_ENABLED               #language en-US "Enabled"
> >
> > Perhaps a random question, but ...
> > Why am I seeing this in cleartext in the patch? Is it really a unicode file?
> 
> Given that we support UTF-8 in .uni files these days, and the fact
> that all characters used are in the 7-bit ASCII range, it doesn't
> really make a difference, I guess.

Fair enough.

/
    Leif