Re: [PATCH] Silicon/SynQuacer/PlatformDxe: enable spread spectrum mode for ASM1061 SATA

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On 24 January 2018 at 11:10, Leif Lindholm <leif.lindholm@linaro.org> wrote:
> On Wed, Jan 24, 2018 at 10:40:52AM +0000, Ard Biesheuvel wrote:
>> The ASM1061 SATA controller integrated into the DeveloperBox board
>> emits too much electromagnetic radiation, so it needs spread spectrum
>> mode enabled.
>
> I presume the spectrum mode is on the PCIe side rather than the SATA
> side? Can this be explicitly mentioned?
>
>> Contributed-under: TianoCore Contribution Agreement 1.1
>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>> ---
>>  Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/{Asmedia118x.c => Asmedia.c} | 79 +++++++++++++++-----
>
> Since you started renaming things, I invoke the right of bikeshedding.
>
> The SATA controller is only Asmedia as well due to happenstance - if
> this file is becoming "various PCI tweaks", can we just call it Pci.c
> (or PciTweaks.c by all means)?
>

Sure

>>  Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/PlatformDxe.inf              |  2 +-
>>  2 files changed, 60 insertions(+), 21 deletions(-)
>>
>> diff --git a/Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/Asmedia118x.c b/Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/Asmedia.c
>> similarity index 64%
>> rename from Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/Asmedia118x.c
>> rename to Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/Asmedia.c
>> index c4cbacd3dff9..6c289fa1892e 100644
>> --- a/Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/Asmedia118x.c
>> +++ b/Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/Asmedia.c
>> @@ -15,9 +15,12 @@
>>  #include "PlatformDxe.h"
>>
>>  #define ASMEDIA_VID                         0x1b21
>> +#define ASM1061_PID                         0x0612
>>  #define ASM1182E_PID                        0x1182
>>  #define ASM1184E_PID                        0x1184
>>
>> +#define ASM1061_SSC_OFFSET                  0xA10
>> +
>>  #define ASM118x_PCIE_CAPABILITY_OFFSET      0x80
>>  #define ASM118x_PCIE_LINK_CONTROL_OFFSET    (ASM118x_PCIE_CAPABILITY_OFFSET + \
>>                                               OFFSET_OF (PCI_CAPABILITY_PCIEXP, \
>> @@ -39,24 +42,10 @@ RetrainAsm1184eDownstreamPort (
>>    IN  EFI_PCI_IO_PROTOCOL   *PciIo
>>    )
>>  {
>> -  UINT16                    PciVidPid[2];
>>    EFI_STATUS                Status;
>>    PCIE_CAP                  Cap;
>>    PCI_REG_PCIE_LINK_CONTROL LinkControl;
>>
>> -  Status = PciIo->Pci.Read (PciIo, EfiPciIoWidthUint16, PCI_VENDOR_ID_OFFSET,
>> -                        ARRAY_SIZE (PciVidPid), &PciVidPid);
>> -  if (EFI_ERROR (Status)) {
>> -    DEBUG ((DEBUG_WARN, "%a: failed to read PCI vendor/product ID - %r\n",
>> -      __FUNCTION__, Status));
>> -    return;
>> -  }
>> -
>> -  if (PciVidPid[0] != ASMEDIA_VID ||
>> -      (PciVidPid[1] != ASM1182E_PID && PciVidPid[1] != ASM1184E_PID)) {
>> -    return;
>> -  }
>> -
>>    //
>>    // The upstream and downstream ports share the same PID/VID, so check
>>    // the port type. This assumes the PCIe Express capability block lives
>> @@ -91,6 +80,34 @@ RetrainAsm1184eDownstreamPort (
>>
>>  STATIC
>>  VOID
>> +EnableAsm1061SpreadSpectrum (
>> +  IN  EFI_PCI_IO_PROTOCOL   *PciIo
>> +  )
>> +{
>> +  EFI_STATUS  Status;
>> +  UINT8       SscVal;
>> +
>> +  DEBUG ((DEBUG_INFO, "%a: enabling spread spectrum mode 0 for ASM1061\n",
>> +    __FUNCTION__));
>> +
>> +  // SSC mode 0~-4000 ppm, 1:1 modulation
>> +
>> +  SscVal = 0;
>> +  Status = PciIo->Pci.Write (PciIo, EfiPciIoWidthUint8, ASM1061_SSC_OFFSET, 1,
>> +                        &SscVal);
>> +  ASSERT_EFI_ERROR (Status);
>> +
>> +  MemoryFence ();
>> +  gBS->Stall (1); // delay at least 100 ns between writes of the same register
>> +
>> +  SscVal = 1;
>> +  Status = PciIo->Pci.Write (PciIo, EfiPciIoWidthUint8, ASM1061_SSC_OFFSET, 1,
>> +                        &SscVal);
>> +  ASSERT_EFI_ERROR (Status);
>> +}
>> +
>> +STATIC
>> +VOID
>>  EFIAPI
>>  OnPciIoProtocolNotify (
>>    IN EFI_EVENT      Event,
>> @@ -101,6 +118,7 @@ OnPciIoProtocolNotify (
>>    EFI_STATUS                Status;
>>    EFI_HANDLE                HandleBuffer;
>>    UINTN                     BufferSize;
>> +  UINT16                    PciVidPid[2];
>>
>>    while (TRUE) {
>>      BufferSize = sizeof (EFI_HANDLE);
>> @@ -114,12 +132,33 @@ OnPciIoProtocolNotify (
>>                      (VOID **)&PciIo);
>>      ASSERT_EFI_ERROR (Status);
>>
>> -    //
>> -    // The ASM1184E 4-port PCIe switch on the DeveloperBox board (and its
>> -    // 2-port sibling of which samples were used in development) needs a
>> -    // little nudge to get it to train the downstream links at Gen2 speed.
>> -    //
>> -    RetrainAsm1184eDownstreamPort (PciIo);
>> +    Status = PciIo->Pci.Read (PciIo, EfiPciIoWidthUint16, PCI_VENDOR_ID_OFFSET,
>> +                          ARRAY_SIZE (PciVidPid), &PciVidPid);
>> +    if (EFI_ERROR (Status)) {
>> +      DEBUG ((DEBUG_WARN, "%a: failed to read PCI vendor/product ID - %r\n",
>> +        __FUNCTION__, Status));
>> +      continue;
>> +    }
>> +
>> +    if (PciVidPid[0] != ASMEDIA_VID) {
>> +      continue;
>> +    }
>> +
>> +    if (PciVidPid[1] == ASM1061_PID) {
>> +      //
>> +      // The ASM1061 SATA controller as integrated into the DeveloperBox design
>> +      // emits too much electromagnetic radiation. So enable spread spectrum
>> +      // mode.
>> +      //
>> +      EnableAsm1061SpreadSpectrum (PciIo);
>> +    } else if (PciVidPid[1] == ASM1182E_PID || PciVidPid[1] == ASM1184E_PID) {
>
> Does this "else if" prevent the SATA controller from training GEN2?
> Could it be just another if?
>

Only if PciVidPid[1] equals ASM1061_PID and ASM1182E_PID/ASM1184E_PID
at the same time.



>
>> +      //
>> +      // The ASM1184E 4-port PCIe switch on the DeveloperBox board (and its
>> +      // 2-port sibling of which samples were used in development) needs a
>> +      // little nudge to get it to train the downstream links at Gen2 speed.
>> +      //
>> +      RetrainAsm1184eDownstreamPort (PciIo);
>> +    }
>>    }
>>  }
>>
>> diff --git a/Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/PlatformDxe.inf b/Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/PlatformDxe.inf
>> index 16412b999a40..64c90ac74e8e 100644
>> --- a/Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/PlatformDxe.inf
>> +++ b/Silicon/Socionext/SynQuacer/Drivers/PlatformDxe/PlatformDxe.inf
>> @@ -23,7 +23,7 @@ [Defines]
>>    ENTRY_POINT                    = PlatformDxeEntryPoint
>>
>>  [Sources]
>> -  Asmedia118x.c
>> +  Asmedia.c
>>    Emmc.c
>>    PlatformDxe.c
>>    PlatformDxeHii.uni
>> --
>> 2.11.0
>>