From e274e0ed0a2ac31d5eaf7c891e4e1d99197517b2 Mon Sep 17 00:00:00 2001
From: Alexandre Bounine <alexandre.bounine@idt.com>
Date: Wed, 27 Oct 2010 15:34:32 -0700
Subject: [PATCH] rapidio: add device access check into the enumeration
Add explicit device access check before performing device enumeration.
This gives a chance to clear possible link error conditions by issuing
safe maintenance read request(s).
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
drivers/rapidio/rio-scan.c | 6 ++++++
drivers/rapidio/rio.c | 2 +-
drivers/rapidio/rio.h | 2 ++
3 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/rapidio/rio-scan.c b/drivers/rapidio/rio-scan.c
index d2ea01872d6a..e3efdf93df5a 100644
--- a/drivers/rapidio/rio-scan.c
+++ b/drivers/rapidio/rio-scan.c
@@ -762,6 +762,12 @@ static int __devinit rio_enum_peer(struct rio_net *net, struct rio_mport *port,
u16 destid;
int tmp;
+ if (rio_mport_chk_dev_access(port,
+ RIO_ANY_DESTID(port->sys_size), hopcount)) {
+ pr_debug("RIO: device access check failed\n");
+ return -1;
+ }
+
if (rio_get_host_deviceid_lock(port, hopcount) == port->host_deviceid) {
pr_debug("RIO: PE already discovered by this host\n");
/*
diff --git a/drivers/rapidio/rio.c b/drivers/rapidio/rio.c
index aefc2a0004d4..fa5e3cbe4c83 100644
--- a/drivers/rapidio/rio.c
+++ b/drivers/rapidio/rio.c
@@ -546,7 +546,7 @@ err_out:
* @destid: Device destination ID in network
* @hopcount: Number of hops into the network
*/
-static int
+int
rio_mport_chk_dev_access(struct rio_mport *mport, u16 destid, u8 hopcount)
{
int i = 0;
diff --git a/drivers/rapidio/rio.h b/drivers/rapidio/rio.h
index bc71ba1d239e..d249a1205c7d 100644
--- a/drivers/rapidio/rio.h
+++ b/drivers/rapidio/rio.h
@@ -24,6 +24,8 @@ extern u32 rio_mport_get_physefb(struct rio_mport *port, int local,
u16 destid, u8 hopcount);
extern u32 rio_mport_get_efb(struct rio_mport *port, int local, u16 destid,
u8 hopcount, u32 from);
+extern int rio_mport_chk_dev_access(struct rio_mport *mport, u16 destid,
+ u8 hopcount);
extern int rio_create_sysfs_dev_files(struct rio_dev *rdev);
extern int rio_enum_mport(struct rio_mport *mport);
extern int rio_disc_mport(struct rio_mport *mport);
--
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