OvmfPkg/XenBusDxe/XenBusDxe.c | 6 ------ 1 file changed, 6 deletions(-)
Calling DisconnectController() on children isn't part of the job of
EFI_DRIVER_BINDING_PROTOCOL.Stop() as it only needs to deallocate
resources allocated in Start(). The disconnection will happen when
both DevicePath and XenBus protocols gets uninstalled.
Reported-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
---
Notes:
Please apply this patch after:
"OvmfPkg/XenBusDxe: Close XenIoProtocol openned by children"
OvmfPkg/XenBusDxe/XenBusDxe.c | 6 ------
1 file changed, 6 deletions(-)
diff --git a/OvmfPkg/XenBusDxe/XenBusDxe.c b/OvmfPkg/XenBusDxe/XenBusDxe.c
index 7c07a96650..634c7b71eb 100644
--- a/OvmfPkg/XenBusDxe/XenBusDxe.c
+++ b/OvmfPkg/XenBusDxe/XenBusDxe.c
@@ -446,12 +446,6 @@ XenBusDxeDriverBindingStop (
continue;
}
ChildData = XENBUS_PRIVATE_DATA_FROM_THIS (XenBusIo);
- Status = gBS->DisconnectController (ChildData->Handle, NULL, NULL);
- if (EFI_ERROR (Status)) {
- DEBUG ((EFI_D_ERROR, "XenBusDxe: error disconnecting child: %r\n",
- Status));
- continue;
- }
Status = gBS->CloseProtocol (Dev->ControllerHandle, &gXenIoProtocolGuid,
Dev->This->DriverBindingHandle, ChildData->Handle);
--
Anthony PERARD
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On 07/01/19 13:14, Anthony PERARD wrote: > Calling DisconnectController() on children isn't part of the job of > EFI_DRIVER_BINDING_PROTOCOL.Stop() as it only needs to deallocate > resources allocated in Start(). The disconnection will happen when > both DevicePath and XenBus protocols gets uninstalled. Correct. In the spec, UninstallMultipleProtocolInterfaces() refers to UninstallProtocolInterface(), and the latter says, [...] Before the protocol interface is removed, an attempt is made to force all the drivers that are consuming the protocol interface to stop consuming that protocol interface. This is done by calling the boot service EFI_BOOT_SERVICES.DisconnectController() for the driver that currently have the protocol interface open with an attribute of EFI_OPEN_PROTOCOL_BY_DRIVER or EFI_OPEN_PROTOCOL_BY_DRIVER | EFI_OPEN_PROTOCOL_EXCLUSIVE. [...] And, the Driver Writer's Guide states, in a Note, When an attempt is made to remove a protocol interface from a handle in the handle database, the UEFI core firmware checks to see if any other UEFI drivers are currently using the services of the protocol to be removed. If UEFI drivers are using that protocol interface, the UEFI core firmware attempts to stop those UEFI drivers with a call to DisconnectController(). This is a quick, legal, and safe way to shut down any protocols associated with this driver's stack. > > Reported-by: Laszlo Ersek <lersek@redhat.com> > Signed-off-by: Anthony PERARD <anthony.perard@citrix.com> > --- > > Notes: > Please apply this patch after: > "OvmfPkg/XenBusDxe: Close XenIoProtocol openned by children" > > OvmfPkg/XenBusDxe/XenBusDxe.c | 6 ------ > 1 file changed, 6 deletions(-) > > diff --git a/OvmfPkg/XenBusDxe/XenBusDxe.c b/OvmfPkg/XenBusDxe/XenBusDxe.c > index 7c07a96650..634c7b71eb 100644 > --- a/OvmfPkg/XenBusDxe/XenBusDxe.c > +++ b/OvmfPkg/XenBusDxe/XenBusDxe.c > @@ -446,12 +446,6 @@ XenBusDxeDriverBindingStop ( > continue; > } > ChildData = XENBUS_PRIVATE_DATA_FROM_THIS (XenBusIo); > - Status = gBS->DisconnectController (ChildData->Handle, NULL, NULL); > - if (EFI_ERROR (Status)) { > - DEBUG ((EFI_D_ERROR, "XenBusDxe: error disconnecting child: %r\n", > - Status)); > - continue; > - } > > Status = gBS->CloseProtocol (Dev->ControllerHandle, &gXenIoProtocolGuid, > Dev->This->DriverBindingHandle, ChildData->Handle); > Reviewed-by: Laszlo Ersek <lersek@redhat.com> -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#43126): https://edk2.groups.io/g/devel/message/43126 Mute This Topic: https://groups.io/mt/32270256/1787277 Group Owner: devel+owner@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [importer@patchew.org] -=-=-=-=-=-=-=-=-=-=-=-
On 07/01/19 13:14, Anthony PERARD wrote: > Calling DisconnectController() on children isn't part of the job of > EFI_DRIVER_BINDING_PROTOCOL.Stop() as it only needs to deallocate > resources allocated in Start(). The disconnection will happen when > both DevicePath and XenBus protocols gets uninstalled. > > Reported-by: Laszlo Ersek <lersek@redhat.com> > Signed-off-by: Anthony PERARD <anthony.perard@citrix.com> > --- > > Notes: > Please apply this patch after: > "OvmfPkg/XenBusDxe: Close XenIoProtocol openned by children" > > OvmfPkg/XenBusDxe/XenBusDxe.c | 6 ------ > 1 file changed, 6 deletions(-) > > diff --git a/OvmfPkg/XenBusDxe/XenBusDxe.c b/OvmfPkg/XenBusDxe/XenBusDxe.c > index 7c07a96650..634c7b71eb 100644 > --- a/OvmfPkg/XenBusDxe/XenBusDxe.c > +++ b/OvmfPkg/XenBusDxe/XenBusDxe.c > @@ -446,12 +446,6 @@ XenBusDxeDriverBindingStop ( > continue; > } > ChildData = XENBUS_PRIVATE_DATA_FROM_THIS (XenBusIo); > - Status = gBS->DisconnectController (ChildData->Handle, NULL, NULL); > - if (EFI_ERROR (Status)) { > - DEBUG ((EFI_D_ERROR, "XenBusDxe: error disconnecting child: %r\n", > - Status)); > - continue; > - } > > Status = gBS->CloseProtocol (Dev->ControllerHandle, &gXenIoProtocolGuid, > Dev->This->DriverBindingHandle, ChildData->Handle); > Commit 6a1f06fadb26. Thanks Laszlo -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#43128): https://edk2.groups.io/g/devel/message/43128 Mute This Topic: https://groups.io/mt/32270256/1787277 Group Owner: devel+owner@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [importer@patchew.org] -=-=-=-=-=-=-=-=-=-=-=-
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