linux-kernel - [PATCH 1/1][resend] check for pci bar restore completion and retry

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1327602353-30966-1-git-send-email-allen.m.kay@intel.com>
Date:	Thu, 26 Jan 2012 10:25:53 -0800
From:	Allen Kay <allen.m.kay@...el.com>
To:	linux-pci-owner@...r.kernel.org
Cc:	jesse.barnes@...el.com, matthew.r.wilcox@...el.com,
	linux-kernel@...r.kernel.org, jean.guyader@...citrix.com,
	eric.chanudet@...rix.com, allen.m.kay@...el.com
Subject: [PATCH 1/1][resend]  check for pci bar restore completion and retry

On some OEM systems, pci_restore_state() is called while FLR has not yet
completed.  As a result, PCI BAR register restore is not successful.  This fix
reads back the restored value and compares it with saved value and re-tries 10
times before giving up.

Signed-off-by: Jean Guyader <jean.guyader@...citrix.com>
Signed-off-by: Eric Chanudet <eric.chanudet@...rix.com>
Signed-off-by: Allen Kay <allen.m.kay@...el.com>
---
 drivers/pci/pci.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index af295bb..0549050 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -959,6 +959,7 @@ void pci_restore_state(struct pci_dev *dev)
 {
 	int i;
 	u32 val;
+	int tries;
 
 	if (!dev->state_saved)
 		return;
@@ -973,12 +974,16 @@ void pci_restore_state(struct pci_dev *dev)
 	 */
 	for (i = 15; i >= 0; i--) {
 		pci_read_config_dword(dev, i * 4, &val);
-		if (val != dev->saved_config_space[i]) {
+		tries = 10;		
+		while (tries && val != dev->saved_config_space[i]) {
 			dev_dbg(&dev->dev, "restoring config "
 				"space at offset %#x (was %#x, writing %#x)\n",
 				i, val, (int)dev->saved_config_space[i]);
 			pci_write_config_dword(dev,i * 4,
 				dev->saved_config_space[i]);
+			pci_read_config_dword(dev, i * 4, &val);
+			mdelay(10);
+			tries--;
 		}
 	}
 	pci_restore_pcix_state(dev);
-- 
1.6.0.6

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/