<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/scsi/libsas/sas_port.c, branch v3.4.95</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>[SCSI] Revert "[SCSI] libsas: fix sas port naming"</title>
<updated>2012-04-23T11:15:53+00:00</updated>
<author>
<name>Dan Williams</name>
<email>dan.j.williams@intel.com</email>
</author>
<published>2012-04-20T06:48:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b4698d88585e23d815506f7f38c48192d944b2eb'/>
<id>b4698d88585e23d815506f7f38c48192d944b2eb</id>
<content type='text'>
This reverts commit a692b0eec5efae382dfa800e8b4b083f172921a7.

Tom reports:

[    8.741033] ------------[ cut here ]------------
[    8.741038] WARNING: at fs/sysfs/dir.c:508 sysfs_add_one+0xc1/0xf0()
[    8.741040] Hardware name: To Be Filled By O.E.M.
[    8.741041] sysfs: cannot create duplicate filename

...and missing 2 out of 4 drives connected to mvsas.  Commit a692b0ee
made the assumption that all the phy ids an lldd registers to libsas are
unique.  However, in the "multi-chip" case mvsas does a rather annoying
duplication of phy ids in the array passed to libsas.  So, for example,
chip0 has phy0-3 at ha phy index 0-3 and chip1 has its phy0-3 at ha phy
index 4-7.  The more natural model would be to create a scsi_host (and
sas_ha) per chip (controller), but for now revert the naming fix which
unfortunately means dealing with unpredictable end-device names for a
bit longer.

Cc: Xiangliang Yu &lt;yuxiangl@marvell.com&gt;
Cc: Patrick Thomson &lt;patrick.s.thomson@intel.com&gt;
Reported-by: Tom Rini &lt;trini@ti.com&gt;
Tested-by: Tom Rini &lt;trini@ti.com&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This reverts commit a692b0eec5efae382dfa800e8b4b083f172921a7.

Tom reports:

[    8.741033] ------------[ cut here ]------------
[    8.741038] WARNING: at fs/sysfs/dir.c:508 sysfs_add_one+0xc1/0xf0()
[    8.741040] Hardware name: To Be Filled By O.E.M.
[    8.741041] sysfs: cannot create duplicate filename

...and missing 2 out of 4 drives connected to mvsas.  Commit a692b0ee
made the assumption that all the phy ids an lldd registers to libsas are
unique.  However, in the "multi-chip" case mvsas does a rather annoying
duplication of phy ids in the array passed to libsas.  So, for example,
chip0 has phy0-3 at ha phy index 0-3 and chip1 has its phy0-3 at ha phy
index 4-7.  The more natural model would be to create a scsi_host (and
sas_ha) per chip (controller), but for now revert the naming fix which
unfortunately means dealing with unpredictable end-device names for a
bit longer.

Cc: Xiangliang Yu &lt;yuxiangl@marvell.com&gt;
Cc: Patrick Thomson &lt;patrick.s.thomson@intel.com&gt;
Reported-by: Tom Rini &lt;trini@ti.com&gt;
Tested-by: Tom Rini &lt;trini@ti.com&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[SCSI] libsas: introduce sas_work to fix sas_drain_work vs sas_queue_work</title>
<updated>2012-04-23T11:03:39+00:00</updated>
<author>
<name>Dan Williams</name>
<email>dan.j.williams@intel.com</email>
</author>
<published>2012-03-09T19:00:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=22b9153faa2263aa89625de25e71c7d44c8dbd16'/>
<id>22b9153faa2263aa89625de25e71c7d44c8dbd16</id>
<content type='text'>
When requeuing work to a draining workqueue the last work instance may
not be idle, so sas_queue_work() must not touch work-&gt;entry.  Introduce
sas_work with a drain_node list_head to have a private list for
collecting work deferred due to drain collision.

Fixes reports like:
  BUG: unable to handle kernel NULL pointer dereference at           (null)
  IP: [&lt;ffffffff810410d4&gt;] process_one_work+0x2e/0x338

Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When requeuing work to a draining workqueue the last work instance may
not be idle, so sas_queue_work() must not touch work-&gt;entry.  Introduce
sas_work with a drain_node list_head to have a private list for
collecting work deferred due to drain collision.

Fixes reports like:
  BUG: unable to handle kernel NULL pointer dereference at           (null)
  IP: [&lt;ffffffff810410d4&gt;] process_one_work+0x2e/0x338

Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[SCSI] libsas: set attached device type and target protocols for local phys</title>
<updated>2012-02-29T21:40:33+00:00</updated>
<author>
<name>Dan Williams</name>
<email>dan.j.williams@intel.com</email>
</author>
<published>2012-01-29T01:24:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=899fcf40f3177697ccfb029d0484cb8ec09a51ca'/>
<id>899fcf40f3177697ccfb029d0484cb8ec09a51ca</id>
<content type='text'>
Before:
$ cat /sys/class/sas_phy/phy-6\:3/device_type
none
$ cat /sys/class/sas_phy/phy-6\:3/target_port_protocols
none

After:
$ cat /sys/class/sas_phy/phy-6\:3/device_type
end device
$ cat /sys/class/sas_phy/phy-6\:3/target_port_protocols
sata

Also downgrade the phy_list_lock to _irq instead of _irqsave since
libsas will never call sas_get_port_device with interrupts disbled.

Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Before:
$ cat /sys/class/sas_phy/phy-6\:3/device_type
none
$ cat /sys/class/sas_phy/phy-6\:3/target_port_protocols
none

After:
$ cat /sys/class/sas_phy/phy-6\:3/device_type
end device
$ cat /sys/class/sas_phy/phy-6\:3/target_port_protocols
sata

Also downgrade the phy_list_lock to _irq instead of _irqsave since
libsas will never call sas_get_port_device with interrupts disbled.

Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[SCSI] libsas: fix sas port naming</title>
<updated>2012-02-29T21:29:06+00:00</updated>
<author>
<name>Dan Williams</name>
<email>dan.j.williams@intel.com</email>
</author>
<published>2012-01-16T21:54:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a692b0eec5efae382dfa800e8b4b083f172921a7'/>
<id>a692b0eec5efae382dfa800e8b4b083f172921a7</id>
<content type='text'>
Make sas-port naming consistent with the expander-attached case whereby
the phy-id is the last digit in the port name.  Otherwise we get the
random behavior of the allocation order.

Reported-by: Patrick Thomson &lt;patrick.s.thomson@intel.com&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Make sas-port naming consistent with the expander-attached case whereby
the phy-id is the last digit in the port name.  Otherwise we get the
random behavior of the allocation order.

Reported-by: Patrick Thomson &lt;patrick.s.thomson@intel.com&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[SCSI] libsas: mark all domain devices gone if root port disappears</title>
<updated>2012-02-29T21:20:55+00:00</updated>
<author>
<name>Dan Williams</name>
<email>dan.j.williams@intel.com</email>
</author>
<published>2012-01-10T22:39:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7d05919aad080074453de880822fe5805875645f'/>
<id>7d05919aad080074453de880822fe5805875645f</id>
<content type='text'>
If the top level expander is hot removed, mark all child devices as gone
before unregistration to short circuit futile recovery.

Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If the top level expander is hot removed, mark all child devices as gone
before unregistration to short circuit futile recovery.

Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[SCSI] libsas: fix sas_find_local_phy(), take phy references</title>
<updated>2012-02-29T19:01:06+00:00</updated>
<author>
<name>Dan Williams</name>
<email>dan.j.williams@intel.com</email>
</author>
<published>2011-12-22T05:33:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f41a0c441c3fe43e79ebeb75584dbb5bfa83e5cd'/>
<id>f41a0c441c3fe43e79ebeb75584dbb5bfa83e5cd</id>
<content type='text'>
In the direct-attached case this routine returns the phy on which this
device was first discovered.  Which is broken if we want to support
wide-targets, as this phy reference can become stale even though the
port is still active.

In the expander-attached case this routine tries to lookup the phy by
scanning the attached sas addresses of the parent expander, and BUG_ONs
if it can't find it.  However since eh and the libsas workqueue run
independently we can still be attempting device recovery via eh after
libsas has recorded the device as detached.  This is even easier to hit
now that eh is blocked while device domain rediscovery takes place, and
that libata is fed more timed out commands increasing the chances that
it will try to recover the ata device.

Arrange for dev-&gt;phy to always point to a last known good phy, it may be
stale after the port is torn down, but it will catch up for wide port
reconfigurations, and never be NULL.

Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In the direct-attached case this routine returns the phy on which this
device was first discovered.  Which is broken if we want to support
wide-targets, as this phy reference can become stale even though the
port is still active.

In the expander-attached case this routine tries to lookup the phy by
scanning the attached sas addresses of the parent expander, and BUG_ONs
if it can't find it.  However since eh and the libsas workqueue run
independently we can still be attempting device recovery via eh after
libsas has recorded the device as detached.  This is even easier to hit
now that eh is blocked while device domain rediscovery takes place, and
that libata is fed more timed out commands increasing the chances that
it will try to recover the ata device.

Arrange for dev-&gt;phy to always point to a last known good phy, it may be
stale after the port is torn down, but it will catch up for wide port
reconfigurations, and never be NULL.

Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[SCSI] libsas: prevent domain rediscovery competing with ata error handling</title>
<updated>2012-02-19T19:52:34+00:00</updated>
<author>
<name>Dan Williams</name>
<email>dan.j.williams@intel.com</email>
</author>
<published>2011-11-18T01:59:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=87c8331fcf72e501c3a3c0cdc5c9391ec72f7cf2'/>
<id>87c8331fcf72e501c3a3c0cdc5c9391ec72f7cf2</id>
<content type='text'>
libata error handling provides for a timeout for link recovery.  libsas
must not rescan for previously known devices in this interval otherwise
it may remove a device that is simply waiting for its link to recover.
Let libata-eh make the determination of when the link is stable and
prevent libsas (host workqueue) from taking action while this
determination is pending.

Using a mutex (ha-&gt;disco_mutex) to flush and disable revalidation while
eh is running requires any discovery action that may block on eh be
moved to its own context outside the lock.  Probing ATA devices
explicitly waits on ata-eh and the cache-flush-io issued during device
removal may also pend awaiting eh completion.  Essentially any rphy
add/remove activity needs to run outside the lock.

This adds two new cleanup states for sas_unregister_domain_devices()
'allocated-but-not-probed', and 'flagged-for-destruction'.  In the
'allocated-but-not-probed' state  dev-&gt;rphy points to a rphy that is
known to have not been through a sas_rphy_add() event.  At domain
teardown check if this device is still pending probe and cleanup
accordingly.  Similarly if a device has already been queued for removal
then sas_unregister_domain_devices has nothing to do.

Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
libata error handling provides for a timeout for link recovery.  libsas
must not rescan for previously known devices in this interval otherwise
it may remove a device that is simply waiting for its link to recover.
Let libata-eh make the determination of when the link is stable and
prevent libsas (host workqueue) from taking action while this
determination is pending.

Using a mutex (ha-&gt;disco_mutex) to flush and disable revalidation while
eh is running requires any discovery action that may block on eh be
moved to its own context outside the lock.  Probing ATA devices
explicitly waits on ata-eh and the cache-flush-io issued during device
removal may also pend awaiting eh completion.  Essentially any rphy
add/remove activity needs to run outside the lock.

This adds two new cleanup states for sas_unregister_domain_devices()
'allocated-but-not-probed', and 'flagged-for-destruction'.  In the
'allocated-but-not-probed' state  dev-&gt;rphy points to a rphy that is
known to have not been through a sas_rphy_add() event.  At domain
teardown check if this device is still pending probe and cleanup
accordingly.  Similarly if a device has already been queued for removal
then sas_unregister_domain_devices has nothing to do.

Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[SCSI] libsas: convert dev-&gt;gone to flags</title>
<updated>2012-02-19T19:51:23+00:00</updated>
<author>
<name>Dan Williams</name>
<email>dan.j.williams@intel.com</email>
</author>
<published>2012-01-07T08:52:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e139942d77a6e3ac83bc322e826668054a8601d6'/>
<id>e139942d77a6e3ac83bc322e826668054a8601d6</id>
<content type='text'>
In preparation for adding tracking of another device state "destroy".

Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In preparation for adding tracking of another device state "destroy".

Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[SCSI] libsas: replace event locks with atomic bitops</title>
<updated>2012-02-19T19:41:04+00:00</updated>
<author>
<name>Dan Williams</name>
<email>dan.j.williams@intel.com</email>
</author>
<published>2011-11-18T01:59:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b15ebe0b5d0b95aeb1d84cae3649df1e0e065e9b'/>
<id>b15ebe0b5d0b95aeb1d84cae3649df1e0e065e9b</id>
<content type='text'>
The locks only served to make sure the pending event bitmask was updated
consistently.

Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The locks only served to make sure the pending event bitmask was updated
consistently.

Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;JBottomley@Parallels.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[SCSI] libsas: fix/amend device gone notification in sas_deform_port()</title>
<updated>2011-05-27T03:49:32+00:00</updated>
<author>
<name>Dan Williams</name>
<email>dan.j.williams@intel.com</email>
</author>
<published>2011-05-24T20:17:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=90f1e10d08bad84f8fd15d3469a60d437d4de64f'/>
<id>90f1e10d08bad84f8fd15d3469a60d437d4de64f</id>
<content type='text'>
Commit 56dd2c06 "libsas: Don't issue commands to devices that have been
hot-removed" edited Darrick's original patch to remove setting 'gone' in
the sas_deform_port() path because that prevented scsi sync cache
commands from being issued when the driver was unloaded.  However, this
allows true device gone notifications (as signaled port phy events) to
trigger sync cache commands to devices that are known to be unreachable.

Teach libsas which sas_deform_port() invocations are likely device gone
events.

Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;jbottomley@parallels.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 56dd2c06 "libsas: Don't issue commands to devices that have been
hot-removed" edited Darrick's original patch to remove setting 'gone' in
the sas_deform_port() path because that prevented scsi sync cache
commands from being issued when the driver was unloaded.  However, this
allows true device gone notifications (as signaled port phy events) to
trigger sync cache commands to devices that are known to be unreachable.

Teach libsas which sas_deform_port() invocations are likely device gone
events.

Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: James Bottomley &lt;jbottomley@parallels.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
