It appears that the wrong fcport H2I message was tested
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Jing Huang <huangj@Brocade.COM>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's an exported symbol of kernel/printk.c
Rename vprintk and dprintk macros to more common VPRINTK and DPRINTK
Add do { } while(0) around macros
Add level to VPRINTK so KERN_CONT can be used a couple of times.
Signed-off-by: Joe Perches <joe@perches.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
String constants that are continued on subsequent lines with \ will cause
spurious whitespace in the resulting output.
Signed-off-by: Joe Perches <joe@perches.com>
Cc: James E.J. Bottomley <James.Bottomley@suse.de>
Cc: Giridhar Malavali <giridhar.malavali@qlogic.com>
Cc: Anirban Chakraborty <anirban.chakraborty@qlogic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In sd_store_cache_type the symbol 'len' is declared twice. Remove the
second declaration to quiet the following sparse warning.
warning: symbol 'len' shadows an earlier one
In sd_probe the variable 'index' is declared as a u32. This variable is
used in a call to ida_get_new which is expecting an int *. Make the
variable an int to quiet the following sparse warning.
warning: incorrect type in argument 2 (different signedness)
There are 4 symbols in the file that are not exported and produce
the following sparse warnings.
warning: symbol 'sd_cdb_cache' was not declared. Should it be static?
warning: symbol 'sd_cdb_pool' was not declared. Should it be static?
warning: symbol 'sd_read_protection_type' was not declared. Should it be static?
warning: symbol 'sd_read_app_tag_own' was not declared. Should it be static?
Make them static to quiet the warnings.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: James E.J. Bottomley <James.Bottomley@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dan's list included:
drivers/scsi/scsi_lib.c +1365 scsi_kill_request(9) warning: variable derefenced in initializer 'cmd'
drivers/scsi/scsi_lib.c +1365 scsi_kill_request(9) warning: variable derefenced before check 'cmd'
We dereference cmd (and possible OOPS if cmd == NULL) before starting the
request so just remove the superfluous debugging code altogether.
[ bart: the potential NULL pointer dereference was finally fixed in
(much later than mine) commit 03b1470 but my patch is still valid ]
Reported-by: Dan Carpenter <error27@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Eugene Teo <eteo@redhat.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In each case, the destination of the allocation has type struct **, so the
elements of the array should have pointer type, not structure type.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@disable sizeof_type_expr@
type T;
T **x;
@@
x =
<+...sizeof(
- T
+ *x
)...+>
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Rolf Eike Beer <eike-kernel@sf-tec.de>
Cc: Joe Perches <joe@perches.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The tag_number reaches dcb->max_command + 1 after the loop, but when
the tag_number equals dcb->max_command an error message is already
issued. The last iteration therefore appears obsolete.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Oliver Neukum <oliver@neukum.name>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The ifdefs are broken so the MMIO code is never compiled and so it's
broken too. Fix them all. Untested as I don't have the hardware.
Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Reviewed-by: Andy Walls <awalls@md.metrocast.net>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove misleading error message that appears after pnp card has been
detected correctly.
Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
At the point where cmnd is initialized, it is tested for NULL, so it
doesn't have to be tested again here.
A simplified version of the semantic match that detects this problem is as
follows (http://coccinelle.lip6.fr/):
// <smpl>
@match exists@
expression x, E;
identifier fld;
@@
* x->fld
... when != \(x = E\|&x\)
* x == NULL
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Besides keeping the line short, the second setting of the MR_DMA_MODE bit
was removed.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Check whether index is within bounds before testing the element.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Willem Riede <osst@riede.org>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block: (149 commits)
block: make sure that REQ_* types are seen even with CONFIG_BLOCK=n
xen-blkfront: fix missing out label
blkdev: fix blkdev_issue_zeroout return value
block: update request stacking methods to support discards
block: fix missing export of blk_types.h
writeback: fix bad _bh spinlock nesting
drbd: revert "delay probes", feature is being re-implemented differently
drbd: Initialize all members of sync_conf to their defaults [Bugz 315]
drbd: Disable delay probes for the upcomming release
writeback: cleanup bdi_register
writeback: add new tracepoints
writeback: remove unnecessary init_timer call
writeback: optimize periodic bdi thread wakeups
writeback: prevent unnecessary bdi threads wakeups
writeback: move bdi threads exiting logic to the forker thread
writeback: restructure bdi forker loop a little
writeback: move last_active to bdi
writeback: do not remove bdi from bdi_list
writeback: simplify bdi code a little
writeback: do not lose wake-ups in bdi threads
...
Fixed up pretty trivial conflicts in drivers/block/virtio_blk.c and
drivers/scsi/scsi_error.c as per Jens.
scsi-ml uses REQ_TYPE_BLOCK_PC for flush requests from file
systems. The definition of REQ_TYPE_BLOCK_PC is that we don't retry
requests even when we can (e.g. UNIT ATTENTION) and we send the
response to the callers (then the callers can decide what they want).
We need a workaround such as the commit
77a4229719 to retry BLOCK_PC flush
requests. We will need the similar workaround for discard requests too
since SCSI-ml handle them as BLOCK_PC internally.
This uses REQ_TYPE_FS for flush requests from file systems instead of
REQ_TYPE_BLOCK_PC.
scsi-ml retries only REQ_TYPE_FS requests that have data to
transfer when we can retry them (e.g. UNIT_ATTENTION). However, we
also need to retry REQ_TYPE_FS requests without data because the
callers don't.
This also changes scsi_check_sense() to retry all the REQ_TYPE_FS
requests when appropriate. Thanks to scsi_noretry_cmd(),
REQ_TYPE_BLOCK_PC requests don't be retried as before.
Note that basically, this reverts the commit
77a4229719 since now we use REQ_TYPE_FS
for flush requests.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Jens, any reason why this isn't included in your for-2.6.36 yet?
=
From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Subject: [PATCH resend] scsi: convert discard to REQ_TYPE_FS from REQ_TYPE_BLOCK_PC
The block layer (file systems) sends discard requests as REQ_TYPE_FS
(the role of REQ_TYPE_FS is that setting up commands and interpreting
the results). But SCSI-ml treats discard requests as
REQ_TYPE_BLOCK_PC.
scsi-ml can handle discard requests as REQ_TYPE_FS
easily. scsi_setup_discard_cmnd() sets up struct request and the bio
nicely. Only remaining issue is that discard requests can't be
completed partially so we need to modify sd_done.
This conversion also fixes the problem that discard requests aren't
retried when possible (e.g. UNIT ATTENTION).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Every user of the BKL in the sd driver is the
result of the pushdown from the block layer
into the open/close/ioctl functions.
The only place that used to rely on the BKL is
the sdkp->openers variable, which gets converted
into an atomic_t.
Nothing else seems to rely on the BKL, since the
functions do not touch global data without holding
another lock, and the open/close functions are
still protected from concurrent execution using
the bdev->bd_mutex.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: linux-scsi@vger.kernel.org
Cc: "James E.J. Bottomley" <James.Bottomley@suse.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
The open and release block_device_operations are currently
called with the BKL held. In order to change that, we must
first make sure that all drivers that currently rely
on this have no regressions.
This blindly pushes the BKL into all .open and .release
operations for all block drivers to prepare for the
next step. The drivers can subsequently replace the BKL
with their own locks or remove it completely when it can
be shown that it is not needed.
The functions blkdev_get and blkdev_put are the only
remaining users of the big kernel lock in the block
layer, besides a few uses in the ioctl code, none
of which need to serialize with blkdev_{get,put}.
Most of these two functions is also under the protection
of bdev->bd_mutex, including the actual calls to
->open and ->release, and the common code does not
access any global data structures that need the BKL.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
As a preparation for the removal of the big kernel
lock in the block layer, this removes the BKL
from the common ioctl handling code, moving it
into every single driver still using it.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
We leak a page allocated for discard on some error conditions
(e.g. scsi_prep_state_check returns BLKPREP_DEFER in
scsi_setup_blk_pc_cmnd).
We unprep on requests that weren't prepped in the error path of
scsi_init_io. It makes the error path to clean up scsi commands messy.
Let's strictly apply the rule that we can't unprep on a request that
wasn't prepped.
Calling just scsi_put_command() in the error path of scsi_init_io() is
enough. We don't set REQ_DONTPREP yet.
scsi_setup_discard_cmnd can safely free a page on the error case with
the above rule.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This is for block's for-2.6.36.
We need to reset q->unprep_rq_fn in sd_remove. Otherwise we hit kernel
oops if we access to a scsi disk device via sg after removing scsi
disk module.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
scsi-ml builds flush requests via q->prepare_flush_fn(), however,
builds discard requests via q->prep_rq_fn.
Using two different mechnisms for the similar requests (building
commands in SCSI ULD) doesn't make sense.
Handing both via q->prep_rq_fn makes the code design simpler.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: James Bottomley <James.Bottomley@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
- sd_done isn't called for pc request so we never call the code.
- we use sd_unprep to free discard page now.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This fixes discard page leak by using q->unprep_rq_fn facility.
q->unprep_rq_fn is called when all the data buffer (req->bio and
scsi_data_buffer) in the request is freed.
sd_unprep() uses rq->buffer to free discard page allocated in
sd_prepare_discard().
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Allocating a fixed payload for discard requests always was a horrible hack,
and it's not coming to byte us when adding support for discard in DM/MD.
So change the code to leave the allocation of a payload to the lowlevel
driver. Unfortunately that means we'll need another hack, which allows
us to update the various block layer length fields indicating that we
have a payload. Instead of hiding this in sd.c, which we already partially
do for UNMAP support add a documented helper in the core block layer for it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Remove the current bio flags and reuse the request flags for the bio, too.
This allows to more easily trace the type of I/O from the filesystem
down to the block driver. There were two flags in the bio that were
missing in the requests: BIO_RW_UNPLUG and BIO_RW_AHEAD. Also I've
renamed two request flags that had a superflous RW in them.
Note that the flags are in bio.h despite having the REQ_ name - as
blkdev.h includes bio.h that is the only way to go for now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Remove all the trivial wrappers for the cmd_type and cmd_flags fields in
struct requests. This allows much easier grepping for different request
types instead of unwinding through macros.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
We can safely remove ISA_DMA_THRESHOLD usage in aha1542. aha1542 uses
ISA_DMA_THRESHOLD to see if:
- the buffers in scatter/list are below 16MB.
- scsi_host is below 16MB.
Both checkings were added in the ancient times but aren't necessary
nowadays since we properly bounce the buffers and allocate scsi_host
below 16MB with non-zero unchecked_isa_dma.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia-2.6:
pcmcia: avoid buffer overflow in pcmcia_setup_isa_irq
pcmcia: do not request windows if you don't need to
pcmcia: insert PCMCIA device resources into resource tree
pcmcia: export resource information to sysfs
pcmcia: use struct resource for PCMCIA devices, part 2
pcmcia: remove memreq_t
pcmcia: move local definitions out of include/pcmcia/cs.h
pcmcia: do not use io_req_t when calling pcmcia_request_io()
pcmcia: do not use io_req_t after call to pcmcia_request_io()
pcmcia: use struct resource for PCMCIA devices
pcmcia: clean up cs.h
pcmcia: use pcmica_{read,write}_config_byte
pcmcia: remove cs_types.h
pcmcia: remove unused flag, simplify headers
pcmcia: remove obsolete CS_EVENT_ definitions
pcmcia: split up central event handler
pcmcia: simplify event callback
pcmcia: remove obsolete ioctl
Conflicts in:
- drivers/staging/comedi/drivers/*
- drivers/staging/wlags49_h2/wl_cs.c
due to dev_info_t and whitespace changes
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (28 commits)
driver core: device_rename's new_name can be const
sysfs: Remove owner field from sysfs struct attribute
powerpc/pci: Remove owner field from attribute initialization in PCI bridge init
regulator: Remove owner field from attribute initialization in regulator core driver
leds: Remove owner field from attribute initialization in bd2802 driver
scsi: Remove owner field from attribute initialization in ARCMSR driver
scsi: Remove owner field from attribute initialization in LPFC driver
cgroupfs: create /sys/fs/cgroup to mount cgroupfs on
Driver core: Add BUS_NOTIFY_BIND_DRIVER
driver core: fix memory leak on one error path in bus_register()
debugfs: no longer needs to depend on SYSFS
sysfs: Fix one more signature discrepancy between sysfs implementation and docs.
sysfs: fix discrepancies between implementation and documentation
dcdbas: remove a redundant smi_data_buf_free in dcdbas_exit
dmi-id: fix a memory leak in dmi_id_init error path
sysfs: sysfs_chmod_file's attr can be const
firmware: Update hotplug script
Driver core: move platform device creation helpers to .init.text (if MODULE=n)
Driver core: reduce duplicated code for platform_device creation
Driver core: use kmemdup in platform_device_add_resources
...
Fake "address-of" expressions that evaluate to NULL generally confuse
readers and can provoke compiler warnings. This patch (as1411) removes
one such fake expression, using an "#ifdef" in its place.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'next-devicetree' of git://git.secretlab.ca/git/linux-2.6: (63 commits)
of/platform: Register of_platform_drivers with an "of:" prefix
of/address: Clean up function declarations
of/spi: call of_register_spi_devices() from spi core code
of: Provide default of_node_to_nid() implementation.
of/device: Make of_device_make_bus_id() usable by other code.
of/irq: Fix endian issues in parsing interrupt specifiers
of: Fix phandle endian issues
of/flattree: fix of_flat_dt_is_compatible() to match the full compatible string
of: remove of_default_bus_ids
of: make of_find_device_by_node generic
microblaze: remove references to of_device and to_of_device
sparc: remove references to of_device and to_of_device
powerpc: remove references to of_device and to_of_device
of/device: Replace of_device with platform_device in includes and core code
of/device: Protect against binding of_platform_drivers to non-OF devices
of: remove asm/of_device.h
of: remove asm/of_platform.h
of/platform: remove all of_bus_type and of_platform_bus_type references
of: Merge of_platform_bus_type with platform_bus_type
drivercore/of: Add OF style matching to platform bus
...
Fix up trivial conflicts in arch/microblaze/kernel/Makefile due to just
some obj-y removals by the devicetree branch, while the microblaze
updates added a new file.
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (276 commits)
[SCSI] zfcp: Trigger logging in the FCP channel on qdio error conditions
[SCSI] zfcp: Introduce experimental support for DIF/DIX
[SCSI] zfcp: Enable data division support for FCP devices
[SCSI] zfcp: Prevent access on uninitialized memory.
[SCSI] zfcp: Post events through FC transport class
[SCSI] zfcp: Cleanup QDIO attachment and improve processing.
[SCSI] zfcp: Cleanup function parameters for sbal value.
[SCSI] zfcp: Use correct width for timer_interval field
[SCSI] zfcp: Remove SCSI device when removing unit
[SCSI] zfcp: Use memdup_user and kstrdup
[SCSI] zfcp: Fix retry after failed "open port" erp action
[SCSI] zfcp: Fail erp after timeout
[SCSI] zfcp: Use forced_reopen in terminate_rport_io callback
[SCSI] zfcp: Register SCSI devices after successful fc_remote_port_add
[SCSI] zfcp: Do not try "forced close" when port is already closed
[SCSI] zfcp: Do not unblock rport from REOPEN_PORT_FORCED
[SCSI] sd: add support for runtime PM
[SCSI] implement runtime Power Management
[SCSI] convert to the new PM framework
[SCSI] Unify SAM_ and SAM_STAT_ macros
...
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1443 commits)
phy/marvell: add 88ec048 support
igb: Program MDICNFG register prior to PHY init
e1000e: correct MAC-PHY interconnect register offset for 82579
hso: Add new product ID
can: Add driver for esd CAN-USB/2 device
l2tp: fix export of header file for userspace
can-raw: Fix skb_orphan_try handling
Revert "net: remove zap_completion_queue"
net: cleanup inclusion
phy/marvell: add 88e1121 interface mode support
u32: negative offset fix
net: Fix a typo from "dev" to "ndev"
igb: Use irq_synchronize per vector when using MSI-X
ixgbevf: fix null pointer dereference due to filter being set for VLAN 0
e1000e: Fix irq_synchronize in MSI-X case
e1000e: register pm_qos request on hardware activation
ip_fragment: fix subtracting PPPOE_SES_HLEN from mtu twice
net: Add getsockopt support for TCP thin-streams
cxgb4: update driver version
cxgb4: add new PCI IDs
...
Manually fix up conflicts in:
- drivers/net/e1000e/netdev.c: due to pm_qos registration
infrastructure changes
- drivers/net/phy/marvell.c: conflict between adding 88ec048 support
and cleaning up the IDs
- drivers/net/wireless/ipw2x00/ipw2100.c: trivial ipw2100_pm_qos_req
conflict (registration change vs marking it static)
Introduce support for DIF/DIX in zfcp: Report the capabilities for the
Scsi_host, map the protection data when issuing I/O requests and
handle the new error codes. Also add the fsf data_direction field to
the hba trace, it is useful information for debugging in that area.
This is an EXPERIMENTAL feature for now.
Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
This patch (as1399) adds runtime-PM support to the sd driver. The
support is unsophisticated: If a SCSI disk device is mounted, or if
its device file is held open, then the device will not be
runtime-suspended; otherwise it will (provided userspace gives
permission by writing "auto" to the sysfs power/control attribute).
In order to make this work, a dev_set_drvdata() call had to be moved
from sd_probe_async() to sd_probe(). Also, a few lines of code were
changed to use a local variable instead of recalculating the address
of an embedded struct device.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
This patch (as1398b) adds runtime PM support to the SCSI layer. Only
the machanism is provided; use of it is up to the various high-level
drivers, and the patch doesn't change any of them. Except for sg --
the patch expicitly prevents a device from being runtime-suspended
while its sg device file is open.
The implementation is simplistic. In general, hosts and targets are
automatically suspended when all their children are asleep, but for
them the runtime-suspend code doesn't actually do anything. (A host's
runtime PM status is propagated up the device tree, though, so a
runtime-PM-aware lower-level driver could power down the host adapter
hardware at the appropriate times.) There are comments indicating
where a transport class might be notified or some other hooks added.
LUNs are runtime-suspended by calling the drivers' existing suspend
handlers (and likewise for runtime-resume). Somewhat arbitrarily, the
implementation delays for 100 ms before suspending an eligible LUN.
This is because there typically are occasions during bootup when the
same device file is opened and closed several times in quick
succession.
The way this all works is that the SCSI core increments a device's
PM-usage count when it is registered. If a high-level driver does
nothing then the device will not be eligible for runtime-suspend
because of the elevated usage count. If a high-level driver wants to
use runtime PM then it can call scsi_autopm_put_device() in its probe
routine to decrement the usage count and scsi_autopm_get_device() in
its remove routine to restore the original count.
Hosts, targets, and LUNs are not suspended while they are being probed
or removed, or while the error handler is running. In fact, a fairly
large part of the patch consists of code to make sure that things
aren't suspended at such times.
[jejb: fix up compile issues in PM config variations]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
This patch (as1397b) converts the SCSI midlayer to use the new PM
callbacks (struct dev_pm_ops). A new source file, scsi_pm.c, is
created to hold the new callback routines, and the existing
suspend/resume code is moved there.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>