Re: Followup : EfiTestManagedDevice() issue in driver GetControllerName() function

["David A. Van Arnem" <dvanarnem@cmlab.biz>]

Hello again,

I think the problem lies in my application, as upon further
investigation, all the handles that publish the Component Name 2
protocol appear to be failing the EfiTestManagedDevice() check (they all
return EFI_UNSUPPORTED).  My eventual goal is, given a buffer of handles
that publish EFI_PCI_IO_PROTOCOL, I would like to locate my specific
device.  I was going to do a string comparison of the ControllerName,
but this doesn't seem to be the right approach.  Is there a recommended
way to accomplish this?

Regards,
David

On 02/21/2017 01:07 PM, David A. Van Arnem wrote:
> Hi all,
> 
> I am developing a UEFI_DRIVER for a custom PCIe device.  I've followed
> the UEFI Driver Model, and implemented the Driver Binding, Component
> Name, and Component Name 2 protocols for my driver.  I'm trying to
> retrieve the Controller Name from this driver in a UEFI_APPLICATION, but
> I've run into an issue.
> 
> In the driver's Start() function, I open the EFI_PCI_IO_PROTOCOL on
> ControllerHandle using the following:
> 
> Status = gBS->OpenProtocol (
>             ControllerHandle,
>             &gEfiPciIoProtocolGuid,
>             (VOID **)&PciIoProtocol,
>             This->DriverBindingHandle,
>             ControllerHandle,
>             EFI_OPEN_PROTOCOL_BY_DRIVER
> 	);
> 
> And leave it open when Start() exits, unless some other part of the
> Start() function fails, which doesn't appear to be happening based on my
> debug messages.
> 
> Following some of the examples in edk2, in my Component Name's
> GetControllerName() function, I used EfiTestManagedDevice() to check
> that the ControllerHandle opened EFI_PCI_IO_PROTOCOL:
> 
> Status = EfiTestManagedDevice (
>             ControllerHandle,
>             g<devicename>DriverBinding.DriverBindingHandle,
>             &gEfiPciIoProtocolGuid
> 	);
> 
> Finally, to get the Controller Name in the application, I first get a
> buffer of handles that publish the ComponentName2 protocol, then walk
> through each and call GetControllerName().
> 
> However, the EfiTestManagedDevice() check in my driver is returning
> EFI_UNSUPPORTED, indicating the protocol is not supported on the handle.
>  Furthermore, after using "load <drivername>.efi" from the shell,
> openinfo on the handle returns:
> 
> Handle 188 (6E16A798)
> ComponentName2
> ComponentName
> DriverBinding
>   Drv[01] Ctrl[ ] Cnt(200) HandProt  Image(<null string>)
> ImageDevicePath
>   Drv[187] Ctrl[ ] Cnt(01) GetProt  Image(<null string>)
> LoadedImage
>   Drv[01] Ctrl[ ] Cnt(09) HandProt  Image(<null string>)
> 
> I feel like maybe I'm missing a step here.  Should I see PciIo in
> openinfo?  Do I need to open a "child" instance of the ControllerHandle
> in my application to get EfiTestManagedDevice() to pass?  I'm not sure
> if that's the right terminology, I'm having a little difficulty
> understanding the "child" concept in this context.  Any tips appreciated.
> 

-- 
Regards,
David Van Arnem
Development Engineer IV
Computer Measurement Laboratory, LLC