Reviewed-by: Ray Ni <ray...@intel.com>
-----Original Message----- From: xueshengfeng <xueshengf...@byosoft.com.cn> Sent: Friday, September 24, 2021 2:31 PM To: devel@edk2.groups.io; Ni, Ray <ray...@intel.com>; Wu, Hao A <hao.a...@intel.com> Cc: Liang, PanlingX <panlingx.li...@intel.com>; Xue, ShengfengX <shengfengx....@intel.com> Subject: [PATCH V5] MdeModulePkg/PciBusDxe: Improve the flow of testing support attributes https://bugzilla.tianocore.org/show_bug.cgi?id=3635 Currently, in order to test the supported attributes, the PciTestSupportedAttribute() will set the command register to 0x27 (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 whether these attributes are set successfully in the device. This 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 This patch fixes this issue by keeping the origina enabled bits when setting 0x27. Signed-off-by: xueshengfeng <xueshengf...@byosoft.com.cn> --- MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c index db1b35f8ef..3a238d4e46 100644 --- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c +++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c @@ -933,6 +933,7 @@ PciTestSupportedAttribute ( ) { EFI_TPL OldTpl; + UINT16 CommandValue; // // Preserve the original value @@ -943,10 +944,12 @@ PciTestSupportedAttribute ( // Raise TPL to high level to disable timer interrupt while the BAR is probed // OldTpl = gBS->RaiseTPL (TPL_HIGH_LEVEL); + CommandValue = *Command | *OldCommand; - PCI_SET_COMMAND_REGISTER (PciIoDevice, *Command); - PCI_READ_COMMAND_REGISTER (PciIoDevice, Command); + PCI_SET_COMMAND_REGISTER (PciIoDevice, CommandValue); + PCI_READ_COMMAND_REGISTER (PciIoDevice, &CommandValue); + *Command = *Command & CommandValue; // // Write back the original value // -- 2.31.1.windows.1 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#81140): https://edk2.groups.io/g/devel/message/81140 Mute This Topic: https://groups.io/mt/85872424/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
