Re: [PATCH] MdeModulePkg/PciBus: Fix system hang when no PCI Option ROM exists

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 12/12/18 4:10 PM, Ruiyu Ni wrote:
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1394
> 
> When there is no PCI option ROM exists, today's logic still creates
> virtual BAR for option ROM using Length = 0, Alignment = (-1).
> It causes the final MEM32 alignment requirement is as big as
> 0xFFFFFFFF_FFFFFFFF.
> 
> The patch fixes this issue by only creating virtual BAR for option
> ROM when there is PCI option ROM.
> 
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
> Cc: Chiu Chasel <chasel.chiu@intel.com>
> Cc: Hao A Wu <hao.a.wu@intel.com>
> Cc: Jian J Wang <jian.j.wang@intel.com>
> ---
>  MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c
> index 7255bcfbbc..ee5c77147e 100644
> --- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c
> +++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciLib.c
> @@ -515,10 +515,12 @@ PciHostBridgeResourceAllocator (
>        // All devices' Option ROM share the same MEM32 resource.
>        //
>        MaxOptionRomSize = GetMaxOptionRomSize (RootBridgeDev);
> -      RootBridgeDev->PciBar[0].BarType   = PciBarTypeOpRom;
> -      RootBridgeDev->PciBar[0].Length    = MaxOptionRomSize;
> -      RootBridgeDev->PciBar[0].Alignment = MaxOptionRomSize - 1;
> -      GetResourceFromDevice (RootBridgeDev, IoBridge, Mem32Bridge, PMem32Bridge, Mem64Bridge, PMem64Bridge);
> +      if (MaxOptionRomSize != 0) {
> +        RootBridgeDev->PciBar[0].BarType   = PciBarTypeOpRom;
> +        RootBridgeDev->PciBar[0].Length    = MaxOptionRomSize;
> +        RootBridgeDev->PciBar[0].Alignment = MaxOptionRomSize - 1;
> +        GetResourceFromDevice (RootBridgeDev, IoBridge, Mem32Bridge, PMem32Bridge, Mem64Bridge, PMem64Bridge);
> +      }
>  
>        //
>        // Create resourcemap by going through all the devices subject to this root bridge
> 

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>