From 267ef3179177cc345e5c1a550cd187a6e5cc8e69 Mon Sep 17 00:00:00 2001
From: Michael Brown <mcb30@ipxe.org>
Date: Tue, 11 Jan 2011 01:37:27 +0000
Subject: [PATCH] [pci] Allow pci_vpd_init() return status to be ignored

Most xxx_init() functions are void functions with no failure cases.
Allow pci_vpd_init() to be used in the same way.  (Subsequent calls to
pci_vpd_read() etc. will fail if pci_vpd_init() fails.)

Signed-off-by: Michael Brown <mcb30@ipxe.org>
---
 src/drivers/bus/pcivpd.c  |  8 ++++++++
 src/include/ipxe/pcivpd.h | 11 +++++++++++
 2 files changed, 19 insertions(+)

diff --git a/src/drivers/bus/pcivpd.c b/src/drivers/bus/pcivpd.c
index 1f7d832b..1ee6c641 100644
--- a/src/drivers/bus/pcivpd.c
+++ b/src/drivers/bus/pcivpd.c
@@ -73,6 +73,10 @@ static int pci_vpd_read_dword ( struct pci_vpd *vpd, int address,
 	unsigned int retries;
 	uint16_t flag;
 
+	/* Fail if no VPD present */
+	if ( ! cap )
+		return -ENOTTY;
+
 	/* Return cached value, if present */
 	if ( pci_vpd_cache_is_valid ( vpd ) &&
 	     ( vpd->cache.address == address ) ) {
@@ -127,6 +131,10 @@ static int pci_vpd_write_dword ( struct pci_vpd *vpd, int address,
 	unsigned int retries;
 	uint16_t flag;
 
+	/* Fail if no VPD present */
+	if ( ! cap )
+		return -ENOTTY;
+
 	/* Invalidate cache */
 	pci_vpd_invalidate_cache ( vpd );
 
diff --git a/src/include/ipxe/pcivpd.h b/src/include/ipxe/pcivpd.h
index 8b973ea1..469ec29f 100644
--- a/src/include/ipxe/pcivpd.h
+++ b/src/include/ipxe/pcivpd.h
@@ -133,6 +133,17 @@ struct pci_vpd {
 	struct pci_vpd_cache cache;
 };
 
+/**
+ * Check for presence of PCI VPD
+ *
+ * @v vpd		PCI VPD
+ * @ret is_present	VPD is present
+ */
+static inline __attribute__ (( always_inline )) int
+pci_vpd_is_present ( struct pci_vpd *vpd ) {
+	return ( vpd->cap != 0 );
+}
+
 /**
  * Check if PCI VPD read cache is valid
  *