Shengfeng: Please update the patch title as PackageName ModuleName: Description. And, please run BaseTools\Scripts\PatchCheck.py to check the patch format.
For this patch, I don't review the code change. Please remove my reviewed-by. Thanks Liming > -----邮件原件----- > 发件人: xueshengfeng <xueshengf...@byosoft.com.cn> > 发送时间: 2021年9月22日 18:10 > 收件人: devel@edk2.groups.io; gaolim...@byosoft.com.cn; > hao.a...@intel.com; ray...@intel.com > 抄送: shengfengx....@intel.com; panlingx.li...@intel.com > 主题: [PATCH V2] On branch PCIBus dulePkg/PciBusDxe: > PciTestSupportedAttribute logic should be changed. > > REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3635 > > Currently, PciTestSupportedAttribute() set the bits > (EFI_PCI_COMMAND_IO_SPACE, > EFI_PCI_COMMAND_MEMORY_SPACE, > EFI_PCI_COMMAND_BUS_MASTER, > EFI_PCI_COMMAND_VGA_PALETTE_SNOOP) firstly, > and then read back to check whethers these attributes are set > successfully in the device. > The flow is below: > 1), read the original register value > 2), set to the input register value > 3), read back the register value, return this value as output 4), > restore the original value. > > This flow will cause the other enabled bits (other than > EFI_PCI_COMMAND_IO_SPACE, EFI_PCI_COMMAND_MEMORY_SPACE, > EFI_PCI_COMMAND_BUS_MASTER, > EFI_PCI_COMMAND_VGA_PALETTE_SNOOP) be > cleared for a short of time. > Below are the new suggested flow: > 1), read the original register value. > 2), set to input register value OR(|) the original register value. > 3), read back the register value, return the value AND(&) the input > command value as output. > 4), restore the original value > > This flow can keep the enabled bits unchanged, and keep the > original function feature. > > Signed-off-by: shengfengx....@intel.com > Reviewed-by: gaolim...@byosoft.com.cn > --- > MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c > b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c > index db1b35f8ef..542e84424b 100644 > --- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c > +++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c > @@ -933,6 +933,7 @@ PciTestSupportedAttribute ( > ) > { > EFI_TPL OldTpl; > + UINT16 CommandTemp; > > // > // Preserve the original value > @@ -944,9 +945,10 @@ PciTestSupportedAttribute ( > // > OldTpl = gBS->RaiseTPL (TPL_HIGH_LEVEL); > > - PCI_SET_COMMAND_REGISTER (PciIoDevice, *Command); > - PCI_READ_COMMAND_REGISTER (PciIoDevice, Command); > + PCI_SET_COMMAND_REGISTER (PciIoDevice, (*Command | > *OldCommand)); > + PCI_READ_COMMAND_REGISTER (PciIoDevice, &CommandTemp); > > + *Command = (*Command) & CommandTemp; > // > // Write back the original value > // > -- > 2.31.1.windows.1 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#81005): https://edk2.groups.io/g/devel/message/81005 Mute This Topic: https://groups.io/mt/85806306/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
