From b6e2ea03b031b6366d2cc3b69d19508763ea1f8a Mon Sep 17 00:00:00 2001
From: Michael Brown <mcb30@ipxe.org>
Date: Mon, 30 Nov 2020 17:48:52 +0000
Subject: [PATCH] [efi] Veto the HP XhciDxe Driver

The HP XhciDxe driver (observed on an HP EliteBook 840 G6) does not
respond correctly to driver disconnection, and will leave the PciIo
protocol instance opened with BY_DRIVER attributes even after
returning successfully from its Stop() method.  This prevents iPXE
from subsequently connecting to the PCI device handle.

Veto this driver if the iPXE build includes a native xHCI driver.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
---
 src/interface/efi/efi_veto.c | 46 ++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/src/interface/efi/efi_veto.c b/src/interface/efi/efi_veto.c
index 1f7cc712e..ad501f262 100644
--- a/src/interface/efi/efi_veto.c
+++ b/src/interface/efi/efi_veto.c
@@ -24,6 +24,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <string.h>
 #include <errno.h>
 #include <ipxe/settings.h>
+#include <ipxe/pci.h>
 #include <ipxe/efi/efi.h>
 #include <ipxe/efi/Protocol/DriverBinding.h>
 #include <ipxe/efi/Protocol/LoadedImage.h>
@@ -391,12 +392,57 @@ efi_veto_dell_ip4config ( EFI_DRIVER_BINDING_PROTOCOL *binding __unused,
 	return 1;
 }
 
+/**
+ * Veto HP XhciDxe driver
+ *
+ * @v binding		Driver binding protocol
+ * @v loaded		Loaded image protocol
+ * @v wtf		Component name protocol, if present
+ * @v manufacturer	Manufacturer name, if present
+ * @v name		Driver name, if present
+ * @ret vetoed		Driver is to be vetoed
+ */
+static int
+efi_veto_hp_xhci ( EFI_DRIVER_BINDING_PROTOCOL *binding __unused,
+		   EFI_LOADED_IMAGE_PROTOCOL *loaded __unused,
+		   EFI_COMPONENT_NAME_PROTOCOL *wtf __unused,
+		   const char *manufacturer, const CHAR16 *name ) {
+	static const CHAR16 xhci[] = L"Usb Xhci Driver";
+	static const char *hp = "HP";
+	struct pci_driver *driver;
+
+	/* Check manufacturer and driver name */
+	if ( ! manufacturer )
+		return 0;
+	if ( ! name )
+		return 0;
+	if ( strcmp ( manufacturer, hp ) != 0 )
+		return 0;
+	if ( memcmp ( name, xhci, sizeof ( xhci ) ) != 0 )
+		return 0;
+
+	/* Veto driver only if we have our own xHCI driver */
+	for_each_table_entry ( driver, PCI_DRIVERS ) {
+		if ( driver->class.class ==
+		     PCI_CLASS ( PCI_CLASS_SERIAL, PCI_CLASS_SERIAL_USB,
+				 PCI_CLASS_SERIAL_USB_XHCI ) ) {
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
 /** Driver vetoes */
 static struct efi_veto efi_vetoes[] = {
 	{
 		.name = "Dell Ip4Config",
 		.veto = efi_veto_dell_ip4config,
 	},
+	{
+		.name = "HP Xhci",
+		.veto = efi_veto_hp_xhci,
+	},
 };
 
 /**
-- 
2.47.2