Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
host no, bus, target, lun, scsi_device_type
for hba mode add: box and bay information
report if the path is active/inactive
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
need to add PMC to copyright notice and update the Hewlett-Packard
copyright notification.
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Justin Lindley <justin.lindley@pmcs.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Synchronize completion the reset with completion of outstanding commands
Extending the newly-added synchronous abort functionality,
now also synchronize resets with the completion of outstanding commands.
Rename the wait queue to reflect the fact that it's being used for both
types of waits. Also, don't complete commands which are terminated
due to a reset operation.
fix for controller lockup during reset
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Hannes Reinecke <hare@Suse.de>
Signed-off-by: Webb Scales <webbnh@hp.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Rework slave allocation:
- separate the tagging support setup from the hostdata setup
- make the hostdata setup act consistently when the lookup fails
- make the hostdata setup act consistently when the device is not added
- set up the queue depth consistently across these scenarios
- if the block layer mq support is not available, explicitly enable and
activate the SCSI layer tcq support (and do this at allocation-time so
that the tags will be available for INQUIRY commands)
Tweak slave configuration so that devices which are masked are also
not attached.
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Hannes Reinecke <hare@Suse.de>
Signed-off-by: Webb Scales <webbnh@hp.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Add the interrupt number to the interrupt names that
appear in /proc/interrupts, so they are unique
Also, delete the IRQ and DAC prints. Other parts of the kernel
already print the IRQ assignments, and dual-address-cycle support
has not been interesting since the parallel PCI bus went from
32 to 64 bits wide.
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Hannes Reinecke <hare@Suse.de>
Signed-off-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Don't return from the abort request until the target command is complete.
Mark outstanding commands which have a pending abort, and do not send them
to the host if we can avoid it.
If the current command has been aborted, do not call the SCSI command
completion routine from the I/O path: when the abort returns successfully,
the SCSI mid-layer will handle the completion implicitly.
The following race was possible in theory.
1. LLD is requested to abort a scsi command
2. scsi command completes
3. The struct CommandList associated with 2 is made available.
4. new io request to LLD to another LUN re-uses struct CommandList
5. abort handler follows scsi_cmnd->host_scribble and
finds struct CommandList and tries to aborts it.
Now we have aborted the wrong command.
Fix by resetting the scsi_cmd field of struct CommandList
upon completion and making the abort handler check that
the scsi_cmd pointer in the CommadList struct matches the
scsi_cmnd that it has been asked to abort.
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Hannes Reinecke <hare@Suse.de>
Signed-off-by: Webb Scales <webbnh@hp.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
add support for tmf when in ioaccel2 mode
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Hannes Reinecke <hare@Suse.de>
Signed-off-by: Joe Handzik <joseph.t.handzik@hp.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Increase the request size for ioaccel2 path.
The error, if any, returned by hpsa_allocate_ioaccel2_sg_chain_blocks
to hpsa_alloc_ioaccel2_cmd_and_bft should be returned upstream rather
than assumed to be -ENOMEM.
This differs slightly from hpsa_alloc_ioaccel1_cmd_and_bft,
which does not call another hpsa_allocate function and only
has -ENOMEM to return from some kmalloc calls.
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Signed-off-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
use ioaccel2 path to submit I/O to physical drives in HBA mode
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Hannes Reinecke <hare@Suse.de>
Signed-off-by: Joe Handzik <joseph.t.handzik@hp.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Do not send aborts to logical devices that do not support aborts
Instead of relying on what the Smart Array claims for supporting logical
drives, simply try an abort and see how it responds at device discovery
time. This way devices that do support aborts (e.g. MSA2000) can work
and we do not waste time trying to send aborts to logical drives that do
not support them (important for high IOPS devices.)
While rescanning devices only test whether devices support aborts
the first time we encounter a device rather than every time.
Some Smart Arrays required aborts to be sent with tags in
the wrong endian byte order. To avoid having to know about
this, we would send two aborts with tags with each endian order.
On high IOPS devices, this turns out to be not such a hot idea.
So we now have a list of the devices that got the tag backwards,
and we only send it one way.
If all available commands are outstanding and the abort handler
is invoked, the abort handler may not be able to allocate a command
and may busy-wait excessivly. Reserve a small number of commands
for the abort handler and limit the number of concurrent abort
requests to the number of reserved commands.
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Hannes Reinecke <hare@Suse.de>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Cache the ioaccel handle so that when we need to abort commands sent
down the ioaccel2 path, we can look up the LUN ID in h->dev[] instead of
having to do I/O to the controller.
Add a field to elements in h->dev[] to keep track of how the device is exposed
to the SCSI mid layer: Not at all, without an upper level driver
(no_uld_attach) or normally exposed.
Since masked physical devices are now present in h->dev[] array
it would be perfectly possible to do
echo scsi add-single-device 2 2 0 0 > /proc/scsi/scsi
and bring them online. This was previously not allowed for masked
physical devices.
Ensure that the mapping of physical disks to logical drives gets updated in a
consistent way when a RAID migration occurs and is not touched until updates
to it are complete.
now instead of doing CISS_REPORT_PHYSICAL to get the LUNID for
the physical disk in hpsa_get_pdisk_of_ioaccel2(), just get
it out of h->dev[] where we already have it cached.
do not touch phys_disk[] for ioaccel enabled logical drives during rescan
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Hannes Reinecke <hare@Suse.de>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Suggested-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Webb Scales <webbnh@hp.com>
Reviewed-by: Kevin Barnett <Kevin.Barnett@pmcs.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Performance tweak, avoid unnecessary function calls.
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
No need to check whether interrupt pending for MSI(X) and
conversely, no need to check whether MSI(X) interrupts are
being used when checking if interrupts are pending.
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Performance enhancement. Remove spin_locks from the driver.
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Empirically, this improves performance slightly (~2% max IOPS) by
allowing cmd_alloc to remember where it left off searching for
free commands between calls instead of always starting its search
at command 0.
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Signed-off-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This means changing the allocator to reference count commands.
The reference count is now the authoritative indicator of whether a
command is allocated or not. The h->cmd_pool_bits bitmap is now
only a heuristic hint to speed up the allocation process, it is no
longer the authoritative record of allocated commands.
Since we changed the command allocator to use reference counting
as the authoritative indicator of whether a command is allocated,
fail_all_outstanding_cmds needs to use the reference count not
h->cmd_pool_bits for this purpose.
Fix hpsa_drain_accel_commands to use the reference count as the
authoritative indicator of whether a command is allocated instead of
the h->cmd_pool_bits bitmap.
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
When using the ioaccel submission methods, requests destined for RAID volumes
are sometimes diverted to physical devices. The OS has no or limited
knowledge of these physical devices, so it is up to the driver to avoid
pushing the device too hard. It is better to honor the physical device queue
limit rather than making the device spew zillions of TASK SET FULL responses.
This is so that hpsa based devices support /sys/block/sdNN/device/queue_type
of simple, which lets the SCSI midlayer automatically adjust the queue_depth
based on TASK SET FULL and GOOD status.
Adjust the queue depth for a new device after it is created based on the
maximum queue depths of the physical devices that constitute the
device. This drops the maximum queue depth from .can_queue of 1024 to
something like 174 for single-drive RAID-0, 348 for two-drive RAID-1, etc.
It also adjusts for the ratio of data to parity drives.
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Signed-off-by: Webb Scales <webbnh@hp.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Instead of kicking the commands all the way back to the mid
layer, use a work queue. This enables having a mechanism for
the driver to be able to resubmit the commands down the "normal"
raid path without turning off the ioaccel feature entirely
whenever an error is encountered on the ioaccel path, and
prevent excessive rescanning of devices.
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The original reasoning behind doing this was faulty. An error
of some sort would be encountered, accelerated i/o would be
disabled for that logical drive, the command would be kicked
back out to the SCSI midlayer for a retry, and since i/o accelerator
mode was disabled, it would get retried down the RAID path.
However, something needs to turn ioaccellerator mode back on,
and this rescan request was what did that. However, it was racy,
and extremely bad for performance to rescan all devices, so,
don't do that.
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
By not doing maintaining a list of queued commands, we can eliminate some spin
locking in the main i/o path and gain significant improvement in IOPS. Remove
the queuing code and the code that calls it; remove now-unused interrupt code;
remove DIRECT_LOOKUP_BIT.
Now that the passthru commands share the same command pool as
the main i/o path, and the total size of the pool is less than
or equal to the number of commands that will fit in the hardware
fifo, there is no need to check to see if we are exceeding the
hardware fifo's depth.
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
We have commands reserved for internal use.
This is laying the groundwork for removing the internal
queue of commands from the driver so that the locks that
protect that queue may be removed.
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
We need to reserve some commands for device rescans,
aborts, and the pass through ioctls, etc. so we cannot
give them all to the scsi mid layer.
This is in preparation for removing cmd_special_alloc and
cmd_special_free so that we can stop queuing commands internally
in the driver so that we can remove the locks thta protect the
queue that we will no longer have.
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Use atomics for commands_outstanding instead of protecting with spin locks.
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Stephen M. Cameron <stephenmcameron@gmail.com>
Reviewed-by: Joe Handzik <joseph.t.handzik@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Clean up issues reported when running sparse.
Signed-off-by: Don Brace <don.brace@pmcs.com>
Reviewed-by: Webb Scales <webb.scales@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
CTLR_STATE_CHANGE_EVENT and CTLR_STATE_CHANGE_EVENT_REDUNDANT_CNTRL
do not require rescans to be initiated. Current firmware filters out
these events already, but some out of date firmware doesn't, so the
driver needs to filter them out too. Without this change and with out
of date firmware you may see the driver spending a lot of time
scanning devices unnecessarily on some Smart Arrays.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Reviewed-by: Justin Lindley <justin.lindley@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
for controllers which support either of the ioaccel transport methods.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Reviewed-by: Mike Miller <michael.miller@canonical.com>
Reviewed-by: Joe Handzik <joseph.t.handzik@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Avoid excessive locking by using per-cpu variable for lockup_detected
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Reviewed-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Now that we can allocate more than 4 reply queues (up to 64)
we shouldn't try to make them share the same allocation but
should allocate them separately.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Reviewed-by: Mike Miller <michael.miller@canonical.com>
Reviewed-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
They are not completely free of cost when disabled and
when enabled emitting debug output for every command
submitted produces far too much output to be useful.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Reviewed-by: Mike Miller <michael.miller@canonical.com>
Reviewed-by: Webb Scales <webb.scales@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The fields "major", "max_outstanding", and "usage_count"
of struct ctlr_info were not used for anything.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Reviewed-by: Mike Miller <michael.miller@canonical.com>
Reviewed-by: Webb Scales <webb.scales@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
And while we're at it fix a magic number
Signed-off-by: Joe Handzik <joseph.t.handzik@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This allows exposing physical disks behind Smart
Array controllers to the OS (if the controller
has the right firmware and is in "hba" mode)
Signed-off-by: Joe Handzik <joseph.t.handzik@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Do not expose drives that are undergoing a format immediately
to the OS, instead wait until they are ready before bringing
them online. This is so that logical drives created with
"rapid parity initialization" do not get immediately kicked
off the system for being unresponsive.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Do no rescan on every events -- way too many rescans are
triggered if we don't filter the events. Limit rescans
to be triggered by the following set of events:
* controller state change
* enclosure hot plug
* physical drive state change
* logical drive state change
* redundant controller state change
* accelerated io enabled/disabled
* accelerated io configuration change
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Allow driver to schedule a rescan whenever a request fails on the ioaccel2 path.
This eliminates the possibility of driver getting stuck in non-ioaccel mode.
IOaccel mode (HP SSD Smart Path) is disabled by driver upon error detection.
Driver relied on idea that request would be retried through normal path, and a
subsequent error would occur on that path, and be processed by controller
firmware. As part of that process, controller disables ioaccel mode and later
reinstates it, signalling driver to change modes.
In some error cases, the error will not duplicate on the standard path,
so the driver could get stuck in non-ioaccel mode.
To avoid that, we allow driver to request a rescan during the next run of the
rescan thread.
Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Allow SSD Smart Path for a controller to be disabled by
the user, regardless of settings in controller firmware
or array configuration.
To disable: echo 0 > /sys/class/scsi_host/host<id>/acciopath_status
To re-enable: echo 1 > /sys/class/scsi_host/host<id>/acciopath_status
To check state: cat /sys/class/scsi_host/host<id>/acciopath_status
Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Joe Handzik <Joseph.T.Handzik@hp.com>
Signed-off-by: Mike Miller <michael.miller@canonical.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Mike Miller <michael.miller@canonical.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Mike Miller <michael.miller@canonical.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
For shared SAS configurations, hosts need to poll Smart Arrays
periodically in order to be able to detect configuration changes
such as logical drives being added or removed from remote hosts.
A register on the controller indicates when such events have
occurred, and the driver polls the register via a workqueue
and kicks off a rescan of devices if such an event is detected.
Additionally, changes to logical drive raid offload eligibility
are autodetected in this way.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
This enables sending i/o's destined for RAID logical drives
which can be serviced by a single physical disk down a different,
faster i/o path directly to physical drives for certain logical
volumes on SSDs bypassing the Smart Array RAID stack for a
performance improvement.
Signed-off-by: Matt Gates <matthew.gates@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Scott Teel <scott.teel@hp.com>
Signed-off-by: Mike Miller <michael.miller@canonical.com>
Signed-off-by: Don Brace <brace@beardog.cce.hp.com>
Signed-off-by: Joe Handzik <joseph.t.handzik@hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
For certain i/o's to certain devices (unmasked physical disks) we
can bypass the RAID stack firmware and do the i/o to the device
directly and it will be faster.
Signed-off-by: Matt Gates <matthew.gates@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Much simpler and avoids races starting/stopping the thread.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
If a fifo full condition is encountered, i/o requests will stack
up in the h->reqQ queue. The only thing which empties this queue
is start_io, which only gets called when new i/o requests come in.
If none are forthcoming, i/o in h->reqQ will be stalled.
To fix this, whenever fifo full condition is encountered, this
is recorded, and the interrupt handler examines this to see
if a fifo full condition was recently encountered when a
command completes and will call start_io to prevent i/o's in
h->reqQ from getting stuck.
I've only ever seen this problem occur when running specialized
test programs that pound on the the CCISS_PASSTHRU ioctl.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Kevin Barnett