Re: [PATCH edk2-platforms 1/2] Silicon/AMD/Styx: Make PcdSataPortMode 32 bits

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

On 19 August 2017 at 22:41, Alan Ott <alan@softiron.com> wrote:
> Extra bits are needed to accomodate all 14 SATA ports
>
> Signed-off-by: Alan Ott <alan@softiron.com>
> Contributed-under: TianoCore Contribution Agreement 1.0
> ---
>  Silicon/AMD/Styx/AmdStyx.dec                                  | 2 +-
>  Silicon/AMD/Styx/Drivers/StyxSataPlatformDxe/InitController.c | 4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/Silicon/AMD/Styx/AmdStyx.dec b/Silicon/AMD/Styx/AmdStyx.dec
> index ddd5bf4..c6eebe6 100644
> --- a/Silicon/AMD/Styx/AmdStyx.dec
> +++ b/Silicon/AMD/Styx/AmdStyx.dec
> @@ -54,7 +54,7 @@
>    gAmdStyxTokenSpaceGuid.PcdSata0CtrlAxiSlvPort|0xE0300000|UINT32|0x00020000
>    gAmdStyxTokenSpaceGuid.PcdSata0PortCount|8|UINT8|0x00020001
>    gAmdStyxTokenSpaceGuid.PcdSataPi|0xFF|UINT32|0x00020002
> -  gAmdStyxTokenSpaceGuid.PcdSataPortMode|0|UINT16|0x00020003
> +  gAmdStyxTokenSpaceGuid.PcdSataPortMode|0|UINT32|0x00020003
>    gAmdStyxTokenSpaceGuid.PcdSataPortMpsp|TRUE|BOOLEAN|0x00020004
>    gAmdStyxTokenSpaceGuid.PcdSataSmpsSupport|FALSE|BOOLEAN|0x00020005
>    gAmdStyxTokenSpaceGuid.PcdSataSssSupport|TRUE|BOOLEAN|0x00020006
> diff --git a/Silicon/AMD/Styx/Drivers/StyxSataPlatformDxe/InitController.c b/Silicon/AMD/Styx/Drivers/StyxSataPlatformDxe/InitController.c
> index 1958d91..78c6819 100644
> --- a/Silicon/AMD/Styx/Drivers/StyxSataPlatformDxe/InitController.c
> +++ b/Silicon/AMD/Styx/Drivers/StyxSataPlatformDxe/InitController.c
> @@ -110,8 +110,8 @@ InitializeSataController (
>    SataChPerSerdes = FixedPcdGet8 (PcdSataNumChPerSerdes);
>
>    for (PortNum = 0; PortNum < SataPortCount; PortNum += SataChPerSerdes) {
> -    EvenPort = (UINT32)(FixedPcdGet16 (PcdSataPortMode) >> (PortNum * 2)) & 3;
> -    OddPort = (UINT32)(FixedPcdGet16 (PcdSataPortMode) >> ((PortNum+1) * 2)) & 3;
> +    EvenPort = (UINT32)(FixedPcdGet32 (PcdSataPortMode) >> (PortNum * 2)) & 3;
> +    OddPort = (UINT32)(FixedPcdGet32 (PcdSataPortMode) >> ((PortNum+1) * 2)) & 3;
>      SataPhyInit ((StartPort + PortNum) / SataChPerSerdes, EvenPort, OddPort);
>    }
>

This doesn't look right to me. PortNum will always be in the set { 0,
2, 4, 6 } due to SataPortCount being equal to either the port count of
sata 0 or of sata 1. So the top 16 bits of the new PCD are never
referenced, and the port mode for sata 0 ends up being applied to sata
1.

Better use

for (PortNum = StartPort; PortNum < StartPort + SataPortCount; ...)
  ..etc..


Also, this code relies rather heavily on SataChPerSerdes == 2, so we
might want to add an ASSERT () for that.