On 08/27/20 22:40, Paul wrote: > In Acpi10.h, EFI_ACPI_DMA_TRANSFER_TYPE_16_BIT is defined as 0x10, > but should be 0x02 per the ACPI Specification. > > REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2937 > > Cc: Michael D Kinney <michael.d.kin...@intel.com> > Cc: Liming Gao <gaolim...@byosoft.com.cn> > Cc: Zhiguang Liu <zhiguang....@intel.com> > Signed-off-by: Paul G <paul.gri...@amd.com> > --- > MdePkg/Include/IndustryStandard/Acpi10.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/MdePkg/Include/IndustryStandard/Acpi10.h > b/MdePkg/Include/IndustryStandard/Acpi10.h > index fa06eefbb6e6..adeb5ae8c219 100644 > --- a/MdePkg/Include/IndustryStandard/Acpi10.h > +++ b/MdePkg/Include/IndustryStandard/Acpi10.h > @@ -358,7 +358,7 @@ typedef struct { > #define EFI_ACPI_DMA_TRANSFER_TYPE_MASK 0x03 > > #define EFI_ACPI_DMA_TRANSFER_TYPE_8_BIT 0x00 > > #define EFI_ACPI_DMA_TRANSFER_TYPE_8_BIT_AND_16_BIT 0x01 > > -#define EFI_ACPI_DMA_TRANSFER_TYPE_16_BIT 0x10 > > +#define EFI_ACPI_DMA_TRANSFER_TYPE_16_BIT 0x02 > > > > // > > // IO Information >
Good catch. The ACPI spec text was likely cut n' pasted into the edk2 source, and then prefixed with "0x". The spec says, """ Bits [1:0] DMA transfer type preference, _SIZ 00 8-bit only 01 8- and 16-bit 10 16-bit only 11 Reserved """ but that's in binary, not in hexadecimal. In fact, the leading zero on *all four* macros (including EFI_ACPI_DMA_TRANSFER_TYPE_MASK) is misleading. In hex, the leading zero in the current macros stands for bits [7:4], which are completely irrelevant for the _SIZ bit-field in the DMA Descriptor. So optimally we'd have #define EFI_ACPI_DMA_TRANSFER_TYPE_MASK 0x3 #define EFI_ACPI_DMA_TRANSFER_TYPE_8_BIT 0x0 #define EFI_ACPI_DMA_TRANSFER_TYPE_8_BIT_AND_16_BIT 0x1 #define EFI_ACPI_DMA_TRANSFER_TYPE_16_BIT 0x2 But I agree the current patch is OK too: Reviewed-by: Laszlo Ersek <ler...@redhat.com> I also agree it's a bugfix and should be merged now. Thanks Laszlo -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#64760): https://edk2.groups.io/g/devel/message/64760 Mute This Topic: https://groups.io/mt/76462757/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
