After merging the scsi tree, today's linux-next build (powerpc
allyesconfig) failed like this:

In file included from drivers/scsi/mpt3sas/mpt3sas_scsih.c:59:0:
drivers/scsi/mpt3sas/mpt3sas_scsih.c: In function '_scsih_io_done':
drivers/scsi/mpt3sas/mpt3sas_base.h:1414:1: error: inlining failed in call to always_inline 'mpt3sas_scsi_direct_io_get': function body not available
 mpt3sas_scsi_direct_io_get(struct MPT3SAS_ADAPTER *ioc, u16 smid);
 ^
drivers/scsi/mpt3sas/mpt3sas_scsih.c:4448:6: error: called from here
  if (mpt3sas_scsi_direct_io_get(ioc, smid) &&
      ^
In file included from drivers/scsi/mpt3sas/mpt3sas_scsih.c:59:0:
drivers/scsi/mpt3sas/mpt3sas_base.h:1416:1: error: inlining failed in call to always_inline 'mpt3sas_scsi_direct_io_set': function body not available
 mpt3sas_scsi_direct_io_set(struct MPT3SAS_ADAPTER *ioc, u16 smid, u8 direct_io);
 ^
drivers/scsi/mpt3sas/mpt3sas_scsih.c:4454:3: error: called from here
   mpt3sas_scsi_direct_io_set(ioc, smid, 0);
   ^
In file included from drivers/scsi/mpt3sas/mpt3sas_scsih.c:5
9:0:
drivers/scsi/mpt3sas/mpt3sas_base.h:1416:1: error: inlining failed in call to always_inline 'mpt3sas_scsi_direct_io_set': function body not available
 mpt3sas_scsi_direct_io_set(struct MPT3SAS_ADAPTER *ioc, u16 smid, u8 direct_io);
 ^
drivers/scsi/mpt3sas/mpt3sas_scsih.c:4454:3: error: called from here
   mpt3sas_scsi_direct_io_set(ioc, smid, 0);
   ^

Presumably caused by commit

  c84b06a4 ("mpt3sas: Single driver module which supports both SAS 2.0 & SAS 3.0 HBAs")
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

SCSI queue for 4.4.
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

According to SPC-4, in a Mode Select, the PS bit in Mode Pages is
reserved and must be set to 0 by the driver.  In the sd implementation,
function cache_type_store does a Mode Sense, which might set the PS bit
on the read buffer, followed by a Mode Select, which receives the same
buffer, without explicitly clearing the PS bit.  So, in cases where
target supports saving the Mode Page to a non-volatile location, we end
up doing a Mode Select with the PS bit set, which could cause an illegal
request error if the target is checking this.

This was observed on a new firmware change, which was subsequently
reverted, but this changes sd.c to be more compliant with SPC-4.

This patch clears the PS bit in the buffer returned by Mode Select,
right before it is used in the Mode Select command.
Signed-off-by: NGabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

As defined in 4.6.9 of SAM-4, the encoding of LUN is
on 5 bits (max_lun=32) and the current value is only 8.
Set max_lun to IBMVSCSI_MAX_LUN (32).
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

As devices with values greater than that are silently ignored,
this gives some hints to the sys admin to know why he doesn't see
his devices...
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

There is a static checker warning here because "bytes" is controlled by
the user and we cap the upper bound with min() but allow negatives.
Negative bytes will result in some nasty warning messages but are not
super harmful.  Anyway, no one needs negative bytes so let's just check
for it and return NULL.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Replace the use of struct timeval and do_gettimeofday() with
64 bit ktime_get_real_seconds. Prevents 32-bit type overflow
in year 2038 on 32-bit systems.

Driver was using the seconds portion of struct timeval (.tv_secs)
to pass a millseconds timestamp to the firmware. This change maintains
that same behavior using ktime_get_real_seconds.

The structure used to pass the timestamp to firmware is 48 bits and
works fine as long as the top 16 bits are zero and they will be zero
for a long time..ie. thousands of years.

Alternative Change:  Add sub second granularity to timestamp

As noted above, the driver only used the seconds portion of timeval,
ignores the microseconds portion, and by multiplying by 1000 effectively
does a <<10 and always writes zero into timestamp[0].

The alternative change would pass all the bits to the firmware:

        struct timespec64 ts;

        ktime_get_real_ts64(&ts);
        timestamp = ts.tv_sec * MSEC_PER_SEC + ts.tv_nsec / NSEC_PER_MSEC;
Signed-off-by: NAlison Schofield <amsfield22@gmail.com>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

struct mvumi_hs_page2 stores a "seconds_since1970" field which is of
type u64. It is however, written to, using 'struct timeval' which has
a 32-bit seconds field and whose value will overflow in year 2038.
This patch uses ktime_get_real_seconds() instead since it provides a
64-bit seconds value, which is 2038 safe.
Signed-off-by: NTina Ruchandani <ruchandani.tina@gmail.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/be2iscsi/be_main.c: In function 'be_sgl_create_contiguous':
drivers/scsi/be2iscsi/be_main.c:3187:18: warning: logical not is only applied to the left hand side of comparison [-Wlogical-not-parentheses]
  WARN_ON(!length > 0);

gcc version 5.2.1
Signed-off-by: NTim Gardner <tim.gardner@canonical.com>
Cc: Jayamohan Kallickal <jayamohan.kallickal@avagotech.com>
Cc: Minh Tran <minh.tran@avagotech.com>
Cc: John Soni Jose <sony.john-n@avagotech.com>
Cc: "James E.J. Bottomley" <JBottomley@odin.com>
Reported-by: NJoel Stanley <joel@jms.id.au>
Reviewed-by: NManoj Kumar <manoj@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The only user of scsi_prep_async_scan() is scsi_scan_host() and it
handles the situation correctly. Move 'called twice' reporting to debug
level as well.

The issue is observed on Hyper-V: on any device add/remove event storvsc
driver calls scsi_scan_host() and in case previous scan is still running
we get the message and stack dump on console.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Tested-by: NAlex Ng <alexng@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Bump mpt3sas driver version to 09.102.00.00
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Modified the mpt3sas driver to have a single driver module which
supports both SAS 2.0 & SAS 3.0 HBA devices.

* Added SAS 2.0 HBA device IDs to the mpt3sas_pci_table pci table.

* Created two separate SCSI host templates for SAS2 and SAS3 HBAs so
  that, during the driver load time driver can use corresponding host
  template(based the pci device ID) while registering a scsi host
  adapter instance for that pci device.

* Registered two IOCTL devices, mpt2ctl is for SAS2 HBAs & mpt3ctl for
  SAS3 HBAs. Also updated the code to make sure that mpt2ctl device
  processes only those ioctl cmds issued for the SAS2 HBAs and mpt3ctl
  device processes only those ioctl cmds issued for the SAS3 HBAs.

* Added separate indexing for SAS2 and SAS3 HBAs.

* Replaced compile time check 'MPT2SAS_SCSI' to run time check
  'hba_mpi_version_belonged' whereever needed.

* Aliased this merged driver to mpt2sas using MODULE_ALIAS.

* Moved global varaible 'driver_name' to per adapter instance variable.

* Created two raid function template and used corresponding raid
  function templates based on the run time check
  'hba_mpi_version_belonged'.

* Moved mpt2sas_warpdrive.c file from mpt2sas to mpt3sas folder and
  renamed it as mpt3sas_warpdrive.c.

* Also renamed the functions in mpt3sas_warpdrive.c file to follow
  current driver function name convention.

* Updated the Makefile to build mpt3sas_warpdrive.o file for these
  WarpDrive-specific functions.

* Also in function mpt3sas_setup_direct_io(), used sector_div() API
  instead of division operator (which gives compilation errors on 32 bit
  machines).

* Removed mpt2sas files, mpt2sas directory & mpt3sas_module.c file.

* Added module parameter 'hbas_to_enumerate' which permits using this
  merged driver as a legacy mpt2sas driver or as a legacy mpt3sas
  driver.

  Here are the available options for this module parameter:

   0 - Merged driver which enumerates both SAS 2.0 & SAS 3.0 HBAs
   1 - Acts as legacy mpt2sas driver, which enumerates only SAS 2.0 HBAs
   2 - Acts as legacy mpt3sas driver, which enumerates only SAS 3.0 HBAs

* Removed mpt2sas entries from SCSI's Kconfig and Makefile files.
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Bump the mpt2sas driver version to 20.102.00.00 and
Bump the mpt3sas driver version to 9.101.00.00.
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

setpci reset on nytro warpdrive card along with sysfs access and cli
ioctl access resulted in kernel oops

1. pci_access_mutex lock added to provide synchronization between IOCTL,
   sysfs, PCI resource handling path

2. gioc_lock spinlock to protect list operations over multiple
   controllers

This patch is ported from commit 6229b414 ("mpt2sas: setpci reset
kernel oops fix").
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Added OEM Gen2 PnP ID branding names from mpt2sas driver.
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The fw_event_work struct is concurrently referenced at shutdown. Add a
refcount to protect it and refactor the code to use it.

Additionally, refactor _scsih_fw_event_cleanup_queue() such that it no
longer iterates over the list without holding the lock since
_firmware_event_work() concurrently deletes items from the list.

This patch is ported from commit 008549f6 ("mpt2sas: Refcount
fw_events and fix unsafe list usage"). These changes are also required
for mpt3sas.
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

sas_device objects can be referenced concurrently throughout the driver.
We need a way to make sure threads can't delete them out from under each
other. This patch adds the refcount and refactors the code to use it.

Additionally, we cannot iterate over the sas_device_list without holding
the lock or we risk corrupting random memory if items are added or
deleted as we iterate. This patch refactors _scsih_probe_sas() to use
the sas_device_list in a safe way.

This patch is ported from the following mpt2sas driver commit
d224fe0d ("mpt2sas: Refcount sas_device objects and fix unsafe list
usage").
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

A new sysfs shost attribute called "BMR_status" is implemented to report
Backup Rail Monitor status.

This attribute is located in:

        /sys/class/scsi_host/host#/BMR_status

When reading this adapter attribute, the driver will output the state of
GPIO[24]. It returns "0" if BMR is healthy and "1" for failure.

If it returns an empty string then it means that there was an error
while obtaining the BMR status. Check dmesg for what error has occurred.

This sysfs shost attribute is mainly for WarpDrive controllers.

This commit is a port of 6c265660 ("mpt2sas: Provide sysfs attribute
to report Backup Rail Monitor Status").
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Ported the following list of WarpDrive-specific patches:

1. commit 0bdccdb0 ("mpt2sas: WarpDrive
   New product SSS6200 support added")

2. commit 82a45258 ("mpt2sas: WarpDrive
   Infinite command retries due to wrong scsi command entry in MPI
   message")

3. commit ba96bd0b ("mpt2sas: Support
   for greater than 2TB capacity WarpDrive")

4. commit 4da7af94 ("mpt2sas: Do not
   retry a timed out direct IO for Warpdrive")

5. commit daeaa9df ("mpt2sas: Avoid type
   casting for direct I/O commands").

Also set the mpt2_ioctl_iocinfo adapter_type to:

1. MPT3_IOCTL_INTERFACE_SAS3 for Gen3 HBAs

2. MPT2_IOCTL_INTERFACE_SAS2_SSS6200 for Warp Drive

3. MPT2_IOCTL_INTERFACE_SAS2  for other Gen2 HBAs
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This patch stops the driver to invoke kthread (which remove the dead
ioc) for some time while EEH recovery has started.

This patch is a port of commit b4730fb6 ("mpt2sas: fix for driver
fails EEH, recovery from injected pci bus error")'.
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

1. Do not enable MSI-X vectors for SAS2008 B0 controllers

2. Enable a single MSI-X vector for the following controller:

   a. SAS2004
   b. SAS2008
   c. SAS2008_1
   d. SAS2008_2
   e. SAS2008_3
   f. SAS2116_1
   g. SAS2116_2

3. Enable Combined Reply Post Queue Support (i.e. 96 MSI-X vectors)
   for Gen3 Invader/Fury C0 and above revision HBAs

4. Enable Combined Reply Post Queue Support (i.e. 96 MSI-X vectors)
   for all Intruder and Cutlass HBAs
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Avoid sending PHYDISK_HIDDEN RAID action requests to SAS2 controllers
since they don't support it.

Also enable fast_path only for SAS3 HBAs.
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Gen2 HBAs use MPI scatter-gather lists whereas Gen3 HBAs use IEEE
scatter-gather lists. Modify the common code part in such a way that it
will build IEEE SGL tables for Gen3 HBAs and MPI SGL tables for Gen2
HBAs.
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Currently there is a logging level option provided for each of our
drivers in the kernel configuration utility. Users can enable this
option to get more verbose information. By default it is enabled.

Only when this option is enabled will the functions which display the
required information get compiled in.

As we are merging the both drivers we can no longer provide this
configuration option. Remove the SCSI_MPTXSAS_LOGGING entry from Kconfig
and unconditionally enable logging (by removing the #ifdef
CONFIG_SCSI_MPT3SAS_LOGGING preprocessor check conditions) so that all
functions which are defined to display more verbose information get
compiled in.
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

1. Use 'hba_mpi_version_belonged' IOC varable to uniquely identify each
individual generation driver functionality at runtime.

2. Declare global variable 'driver_name' and use this variable while
reserving PCI regions and while allocating the IRQs.
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Remove .c and .h files which are no longer needed from mpt2sas
driver. We are reusing this code from mpt3sas.
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

1. Create a mpt2sas_module.c file for mpt2sas where GEN2 HBA devices
register with PCI, SML, IOCTL subsystems.

2. Updated the Makefile to use the object files from mpt3sas folder.

3. Defined a compilation flag SCSI_MPT2SAS which can be used to not
include those sections of code from mpt3sas driver which are not
required for mpt2sas driver.

4. Inherited automatic diag buffer feature from mpt3sas driver.
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Created a mpt3sas_module.c file for mpt3sas driver where it can register
SAS3 HBA devices with PCI, SML, IOCTL subsystems. Also removed the
corresponding interfaces from mpt3sas_scsih.c file.
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

1. Added mpt2sas driver related macros in mpt3sas header files

2. Made scsi host's, raid class', pci's, ioctl's callback functions
global so that both drivers can use them.
Signed-off-by: NSreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Use a single set of the hardware description headers instead of having
them in the source tree twice.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NSreekanth Reddy <sreekanth.reddy@avagotech.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Function stex_gettime uses 'struct timeval' whose tv_sec value
will overflow on 32-bit systems in year 2038 and beyond. This patch
replaces the use of struct timeval and do_gettimeofday with
ktime_get_real_seconds, which returns a 64-bit seconds value.
Suggested-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NTina Ruchandani <ruchandani.tina@gmail.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Writing a number to /sys/bus/scsi/devices/<sdev>/queue_ramp_up_period
returns the value of that number instead of the number of bytes written.
This behavior can confuse programs expecting POSIX write() semantics.
Fix this by returning the number of bytes written instead.
Signed-off-by: NPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NEwan D. Milne <emilne@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Signed-off-by: NGiridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: NChad Dupuis <chad.dupuis@qlogic.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Explicit logouts from bnx2fc were causing race conditions in either returning
stale SCSI commands or not allowing a target to log back in.
Signed-off-by: NGiridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: NChad Dupuis <chad.dupuis@qlogic.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Signed-off-by: NGiridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: NChad Dupuis <chad.dupuis@qlogic.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Signed-off-by: NGiridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: NChad Dupuis <chad.dupuis@qlogic.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Signed-off-by: NGiridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: NChad Dupuis <chad.dupuis@qlogic.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Signed-off-by: NGiridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: NChad Dupuis <chad.dupuis@qlogic.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Change st driver to allow enabling or disabling debug output
via sysfs file /sys/bus/scsi/drivers/st/debug_flag.

Previously the only way to enable debug output was:

1. loading the driver with the module parameter debug_flag=1
2. an ioctl call (this method was also the only way to dynamically
disable debug output).

To use the ioctl you need a second tape drive (if you are
actively testing the first tape drive) since a second process
cannot open the first tape drive if it is in use.

The this change is only functional if the value of the macro
DEBUG in st.c is a non-zero value (which it is by default).
Signed-off-by: NShane Seymour <shane.seymour@hpe.com>
Reviewed-by: NLaurence Oberman <oberman.l@gmail.com>
Acked-by: NKai Mäkisara <kai.makisara@kolumbus.fi>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Signed-off-by: NSebastian Herbszt <herbszt@gmx.de>
Acked-by: NVasu Dev <vasu.dev@intel.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>