linux-toradex.git/include/linux/libata.h, branch v3.19.7

libata: allow sata_sil24 to opt-out of tag ordered submission

2015-01-19T14:10:07+00:00

Ronny reports: https://bugzilla.kernel.org/show_bug.cgi?id=87101
    "Since commit 8a4aeec8d "libata/ahci: accommodate tag ordered
    controllers" the access to the harddisk on the first SATA-port is
    failing on its first access. The access to the harddisk on the
    second port is working normal.

    When reverting the above commit, access to both harddisks is working
    fine again."

Maintain tag ordered submission as the default, but allow sata_sil24 to
continue with the old behavior.

Cc: 
Cc: Tejun Heo 
Reported-by: Ronny Hegewald 
Signed-off-by: Dan Williams 
Signed-off-by: Tejun Heo

libata: Whitelist SSDs that are known to properly return zeroes after TRIM

2015-01-08T15:35:40+00:00

As defined, the DRAT (Deterministic Read After Trim) and RZAT (Return
Zero After Trim) flags in the ATA Command Set are unreliable in the
sense that they only define what happens if the device successfully
executed the DSM TRIM command. TRIM is only advisory, however, and the
device is free to silently ignore all or parts of the request.

In practice this renders the DRAT and RZAT flags completely useless and
because the results are unpredictable we decided to disable discard in
MD for 3.18 to avoid the risk of data corruption.

Hardware vendors in the real world obviously need better guarantees than
what the standards bodies provide. Unfortuntely those guarantees are
encoded in product requirements documents rather than somewhere we can
key off of them programatically. So we are compelled to disabling
discard_zeroes_data for all devices unless we explicitly have data to
support whitelisting them.

This patch whitelists SSDs from a few of the main vendors. None of the
whitelists are based on written guarantees. They are purely based on
empirical evidence collected from internal and external users that have
tested or qualified these drives in RAID deployments.

The whitelist is only meant as a starting point and is by no means
comprehensive:

   - All intel SSD models except for 510
   - Micron M5?0/M600
   - Samsung SSDs
   - Seagate SSDs

Signed-off-by: Martin K. Petersen 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Tejun Heo

Merge branch 'for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata

2014-12-12T02:52:37+00:00

Pull libata changes from Tejun Heo:
 "The only interesting piece is the support for shingled drives.  The
  changes in libata layer are minimal.  All it does is identifying the
  new class of device and report upwards accordingly"

* 'for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
  libata: Remove FIXME comment in atapi_request_sense()
  sata_rcar: Document deprecated "renesas,rcar-sata"
  sata_rcar: Add clocks to sata_rcar bindings
  ahci_sunxi: Make AHCI_HFLAG_NO_PMP flag configurable with a module option
  libata-scsi: Update SATL for ZAC drives
  libata: Implement ATA_DEV_ZAC
  libsas: use ata_dev_classify()

scsi: drop reason argument from ->change_queue_depth

2014-11-24T13:45:27+00:00

Drop the now unused reason argument from the ->change_queue_depth method.
Also add a return value to scsi_adjust_queue_depth, and rename it to
scsi_change_queue_depth now that it can be used as the default
->change_queue_depth implementation.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Mike Christie 
Reviewed-by: Hannes Reinecke

libata: Implement ATA_DEV_ZAC

2014-11-05T16:22:06+00:00

Add new ATA device type for ZAC devices.

Acked-by: Christoph Hellwig 
Acked-by: Tejun Heo 
Signed-off-by: Hannes Reinecke 
Signed-off-by: Tejun Heo

libata: change ata__printk routines to return void

2014-09-23T14:02:31+00:00

The return value is not used by callers of these functions nor
by uses of all macros so change the functions to return void.

Signed-off-by: Joe Perches 
Signed-off-by: Tejun Heo

libata: introduce ata_host->n_tags to avoid oops on SAS controllers

2014-07-23T14:30:34+00:00

1871ee134b73 ("libata: support the ata host which implements a queue
depth less than 32") directly used ata_port->scsi_host->can_queue from
ata_qc_new() to determine the number of tags supported by the host;
unfortunately, SAS controllers doing SATA don't initialize ->scsi_host
leading to the following oops.

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000058
 IP: [] ata_qc_new_init+0x188/0x1b0
 PGD 0
 Oops: 0002 [#1] SMP
 Modules linked in: isci libsas scsi_transport_sas mgag200 drm_kms_helper ttm
 CPU: 1 PID: 518 Comm: udevd Not tainted 3.16.0-rc6+ #62
 Hardware name: Intel Corporation S2600CO/S2600CO, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013
 task: ffff880c1a00b280 ti: ffff88061a000000 task.ti: ffff88061a000000
 RIP: 0010:[]  [] ata_qc_new_init+0x188/0x1b0
 RSP: 0018:ffff88061a003ae8  EFLAGS: 00010012
 RAX: 0000000000000001 RBX: ffff88000241ca80 RCX: 00000000000000fa
 RDX: 0000000000000020 RSI: 0000000000000020 RDI: ffff8806194aa298
 RBP: ffff88061a003ae8 R08: ffff8806194a8000 R09: 0000000000000000
 R10: 0000000000000000 R11: ffff88000241ca80 R12: ffff88061ad58200
 R13: ffff8806194aa298 R14: ffffffff814e67a0 R15: ffff8806194a8000
 FS:  00007f3ad7fe3840(0000) GS:ffff880627620000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000058 CR3: 000000061a118000 CR4: 00000000001407e0
 Stack:
  ffff88061a003b20 ffffffff814e96e1 ffff88000241ca80 ffff88061ad58200
  ffff8800b6bf6000 ffff880c1c988000 ffff880619903850 ffff88061a003b68
  ffffffffa0056ce1 ffff88061a003b48 0000000013d6e6f8 ffff88000241ca80
 Call Trace:
  [] ata_sas_queuecmd+0xa1/0x430
  [] sas_queuecommand+0x191/0x220 [libsas]
  [] scsi_dispatch_cmd+0x10e/0x300
  [] scsi_request_fn+0x2f5/0x550
  [] __blk_run_queue+0x33/0x40
  [] queue_unplugged+0x2a/0x90
  [] blk_flush_plug_list+0x1b4/0x210
  [] blk_finish_plug+0x14/0x50
  [] __do_page_cache_readahead+0x198/0x1f0
  [] force_page_cache_readahead+0x31/0x50
  [] page_cache_sync_readahead+0x3e/0x50
  [] generic_file_read_iter+0x496/0x5a0
  [] blkdev_read_iter+0x37/0x40
  [] new_sync_read+0x7e/0xb0
  [] vfs_read+0x94/0x170
  [] SyS_read+0x46/0xb0
  [] ? SyS_lseek+0x91/0xb0
  [] system_call_fastpath+0x16/0x1b
 Code: 00 00 00 88 50 29 83 7f 08 01 19 d2 83 e2 f0 83 ea 50 88 50 34 c6 81 1d 02 00 00 40 c6 81 17 02 00 00 00 5d c3 66 0f 1f 44 00 00 <89> 14 25 58 00 00 00

Fix it by introducing ata_host->n_tags which is initialized to
ATA_MAX_QUEUE - 1 in ata_host_init() for SAS controllers and set to
scsi_host_template->can_queue in ata_host_register() for !SAS ones.
As SAS hosts are never registered, this will give them the same
ATA_MAX_QUEUE - 1 as before.  Note that we can't use
scsi_host->can_queue directly for SAS hosts anyway as they can go
higher than the libata maximum.

Signed-off-by: Tejun Heo 
Reported-by: Mike Qiu 
Reported-by: Jesse Brandeburg 
Reported-by: Peter Hurley 
Reported-by: Peter Zijlstra 
Tested-by: Alexey Kardashevskiy 
Fixes: 1871ee134b73 ("libata: support the ata host which implements a queue depth less than 32")
Cc: Kevin Hao 
Cc: Dan Williams 
Cc: stable@vger.kernel.org

libata/ahci: accommodate tag ordered controllers

2014-04-18T19:56:03+00:00

The AHCI spec allows implementations to issue commands in tag order
rather than FIFO order:

	5.3.2.12 P:SelectCmd
	HBA sets pSlotLoc = (pSlotLoc + 1) mod (CAP.NCS + 1)
	or HBA selects the command to issue that has had the
	PxCI bit set to '1' longer than any other command
	pending to be issued.

The result is that commands posted sequentially (time-wise) may play out
of sequence when issued by hardware.

This behavior has likely been hidden by drives that arrange for commands
to complete in issue order.  However, it appears recent drives (two from
different vendors that we have found so far) inflict out-of-order
completions as a matter of course.  So, we need to take care to maintain
ordered submission, otherwise we risk triggering a drive to fall out of
sequential-io automation and back to random-io processing, which incurs
large latency and degrades throughput.

This issue was found in simple benchmarks where QD=2 seq-write
performance was 30-50% *greater* than QD=32 seq-write performance.

Tagging for -stable and making the change globally since it has a low
risk-to-reward ratio.  Also, word is that recent versions of an unnamed
OS also does it this way now.  So, drives in the field are already
experienced with this tag ordering scheme.

Cc: 
Cc: Dave Jiang 
Cc: Ed Ciechanowski 
Reviewed-by: Matthew Wilcox 
Signed-off-by: Dan Williams 
Signed-off-by: Tejun Heo

libata: remove unused ata_sas_port_async_resume() stub

2014-03-19T20:30:23+00:00

Commit bc6e7c4b0d1a "libata, libsas: kill pm_result and related cleanup"
renamed ata_sas_port_async_resume() to ata_sas_port_resume(), but missed
a CONFIG_PM=n stub conversion.  Randy fixed that up in commit
a5a6569959fc "libata.h: add stub for ata_sas_port_resume", but missed
the deletion of the now unused ata_sas_port_async_resume() routine.

Cc: Randy Dunlap 
Signed-off-by: Dan Williams 
Signed-off-by: Tejun Heo

libata.h: add stub for ata_sas_port_resume

2014-03-19T17:56:40+00:00

Fix build error when CONFIG_PM is not enabled by adding a stub
function in .

drivers/scsi/libsas/sas_ata.c: In function 'sas_resume_sata':
drivers/scsi/libsas/sas_ata.c:756:3: error: implicit declaration of function 'ata_sas_port_resume' [-Werror=implicit-function-declaration]

Signed-off-by: Randy Dunlap 
Reported-by: Jim Davis 
Signed-off-by: Tejun Heo 
Cc: Dan Williams