LIBSAS:Issue with cascading of edge expanders

LIBSAS:Issue with cascading of edge expanders

[Srinivas Naga Venkatasatya Pasagadugula]

Hi,

I have some issues with cascading of edge expanders in linux kernel-2.6.31.

Test Environment:
-------------------
Linux Kernel-2.6.31.
I'm using Adaptec ASC-1045/1405 which uses the Marvell 88SE6440 chip and I am using 2.6.31-mvsas driver.

Problem Description.
--------------------
Cold boot of cascading expanders are working fine but hot plug in and plug out of the same is not working properly.

Root Cause:
-------------
After analyzing the same I have figured out the problem is in sas_expander.c (libsas). It is not working when the phy change is occurred to remove the devices or to rediscover the devices.

...... sas_expander.c....
1805 static int sas_discover_new(struct domain_device *dev, int phy_id)

1832         res = sas_ex_discover_devices(dev, phy_id);
1833         if (!res)
1834                 goto out;
..........

Solution:
------------
The same issue doesn't occur after modifying the code like this.
...sas_expander.c...
1832            res = sas_ex_discover_devices(dev, phy_id);
1833        if (res)
1834               goto out;
............

Is this is the fix for the same? Any inputs are highly appreciated.

Thanks
Srinivas.


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-----------------------------------------------------------------------------------------------------------------------

Re: [PATCH] libsas: do not set res = 0 in sas_ex_discover_dev()

[James Bottomley]

On Thu, 2009-11-05 at 15:56 +0800, jack wang wrote:
> Hi, James
> 
> What is the status of this this patch .  we have test it  Srinivas
> have confirmed it does work.
> 
> Please consider to include it in your rc-fixes tree.

OK, this one never actually made it to the list.  I think this was
because all the patches contained text/html attachments which the list
kills sight unseen because it thinks they're spam.  You really have to
make sure you only send text plain and patch attachments for them to get
through.

For simplicity, the patch is below for list review.

James

---

From: jack wang <jack_wang@usish.com>
Subject: [PATCH] libsas: do not set res = 0 in sas_ex_discover_dev()

We should not set res to 0 in function sas_ex_discover_dev  in order to let
it discover it further when wide port hotplug in .

Signed-off-by: Tom Peng <tom_peng@usish.com>
Signed-off-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
---
 drivers/scsi/libsas/sas_expander.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index b338195..33cf988 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -960,7 +960,6 @@ static int sas_ex_discover_dev(struct domain_device *dev, int phy_id)
 
 			}
 		}
-		res = 0;
 	}
 
 	return res;
-- 
1.6.4.2

Re: Re: [PATCH] libsas: do not set res = 0 in sas_ex_discover_dev()

[jack_wang]

OK, this one never actually made it to the list.  I think this was
because all the patches contained text/html attachments which the list
kills sight unseen because it thinks they're spam.  You really have to
make sure you only send text plain and patch attachments for them to get
through.

For simplicity, the patch is below for list review.

James
 [Jack] Sorry for that, We will make sure text/html things will never happen in the future. 
And thanks for you help.
---

From: jack wang <jack_wang@usish.com>
Subject: [PATCH] libsas: do not set res = 0 in sas_ex_discover_dev()

We should not set res to 0 in function sas_ex_discover_dev  in order to let
it discover it further when wide port hotplug in .

Signed-off-by: Tom Peng <tom_peng@usish.com>
Signed-off-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
---
 drivers/scsi/libsas/sas_expander.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index b338195..33cf988 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -960,7 +960,6 @@ static int sas_ex_discover_dev(struct domain_device *dev, int phy_id)
 
 			}
 		}
-		res = 0;
 	}
 
 	return res;
-- 
1.6.4.2