From 5fe204eab174fd474227f23fd47faee4e7a6c000 Mon Sep 17 00:00:00 2001
From: Bjorn Helgaas <bhelgaas@google.com>
Date: Thu, 15 Jul 2021 16:59:59 -0500
Subject: [PATCH] PCI/VPD: Allow access to valid parts of VPD if some is
 invalid
Git-commit: 5fe204eab174fd474227f23fd47faee4e7a6c000
References: jsc#SLE-19359
Patch-mainline: v5.15-rc1

Previously, if we found any error in the VPD, we returned size 0, which
prevents access to all of VPD.  But there may be valid resources in VPD
before the error, and there's no reason to prevent access to those.

"off" covers only VPD resources known to have valid header tags.  In case
of error, return "off" (which may be zero if we haven't found any valid
header tags at all).

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/pci/vpd.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/vpd.c b/drivers/pci/vpd.c
index 602d30220ec4..a85c8b51703a 100644
--- a/drivers/pci/vpd.c
+++ b/drivers/pci/vpd.c
@@ -86,7 +86,7 @@ static size_t pci_vpd_size(struct pci_dev *dev, size_t old_size)
 			if (pci_read_vpd(dev, off + 1, 2, &header[1]) != 2) {
 				pci_warn(dev, "failed VPD read at offset %zu\n",
 					 off + 1);
-				return 0;
+				return off;
 			}
 			size = pci_vpd_lrdt_size(header);
 			if (off + size > PCI_VPD_MAX_SIZE)
@@ -105,13 +105,13 @@ static size_t pci_vpd_size(struct pci_dev *dev, size_t old_size)
 				return off;
 		}
 	}
-	return 0;
+	return off;
 
 error:
 	pci_info(dev, "invalid VPD tag %#04x (size %zu) at offset %zu%s\n",
 		 header[0], size, off, off == 0 ?
 		 "; assume missing optional EEPROM" : "");
-	return 0;
+	return off;
 }
 
 /*
-- 
2.26.2