Original patch (dfa4411c) was buggy.
This is a more proper fix which introduces blk_rq_quiet() macro
alleviating the need for dumb, too short caching variables.

Thanks to Helge Deller and Bart for debugging this.
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Reported-and-tested-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

With 2.6.30-rc2 I face a kernel crash on the 32bit hppa architecture 
due to ide-cd when udev creates the device nodes at startup:

Kernel Fault: Code=26 regs=8ed34c40 (Addr=00000024)
IASQ: 00000000 00000000 IAOQ: 1034b5ac 1034b5b0
 IIR: 4ab30048    ISR: 00000000  IOR: 00000024
 CPU:        0   CR30: 8ed34000 CR31: ffff55ff
 ORIG_R28: 00000000
 IAOQ[0]: ide_complete_rq+0x2c/0x70
 IAOQ[1]: ide_complete_rq+0x30/0x70
 RP(r2): cdrom_newpc_intr+0x178/0x46c
Backtrace:
 [<1035c608>] cdrom_newpc_intr+0x178/0x46c
 [<1034c494>] ide_intr+0x1b0/0x214
 [<1016d284>] handle_IRQ_event+0x70/0x150
 [<1016d4b0>] __do_IRQ+0x14c/0x1cc
 [<102f7864>] superio_interrupt+0x88/0xbc
 [<1016d284>] handle_IRQ_event+0x70/0x150
 [<1016d4b0>] __do_IRQ+0x14c/0x1cc
 [<10112efc>] do_cpu_irq_mask+0x9c/0xd0
 [<10116068>] intr_return+0x0/0x4

This crash seems to happen due to an uninitialized variable "rc".
The compiler even warns about that:
  CC      drivers/ide/ide-cd.o                                                         
/mnt/sda4/home/cvs/parisc/git-kernel/linus-linux-2.6/drivers/ide/ide-cd.c: In function `cdrom_newpc_intr':
/mnt/sda4/home/cvs/parisc/git-kernel/linus-linux-2.6/drivers/ide/ide-cd.c:612: warning: `rc' might be used uninitialized in this function

After applying the trivial patch below, which just initializes 
the variable to zero, the kernel doesn't crash any longer:

Starting the hotplug events dispatcher: udevd.
Synthesizing the initial hotplug events...
hda: command error: status=0x51 { DriveReady SeekComplete Error }
hda: command error: error=0x54 <3>{ AbortedCommand LastFailedSense=0x05 }
ide: failed opcode was: unknown
done.
Signed-off-by: NHelge Deller <deller@gmx.de>
Acked-by: NBorislav Petkov <petkovbb@gmail.com>
Cc: Linus <torvalds@linux-foundation.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Make the case of flushing the drive's cache explicit.

There should be no functional change resulting from this patch.
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Based on earlier work by Borislav Petkov.

Fix intendation in cdrom_decode_status(), no real code changes.

While at it:
- beautify comments

There should be no functional changes caused by this patch.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Based on earlier work by Borislav Petkov.

Unify handling of fs and pc requests in cdrom_decode_status().

While at it:
- remove unreachable code

The only change in functionality is that for pc requests more
detailed error message will be printed for following sense keys:
* ILLEGAL_REQUEST
* DATA_PROTECT
* MEDIUM_ERROR
* BLANK_CHECK
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Based on earlier work by Borislav Petkov.

Convert cdrom_decode_status() to use switch statements in
preparation to unify handling of fs and pc requests.

While at it:
- remove superfluous comments and do minor CodingStyle fixups

There should be no functional changes caused by this patch.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
[bart: extracted from "ide-cd: cleanup cdrom_decode_status" patch]
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

There should be no functional change resulting from this patch.
Suggested-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

There should be no functional change resulting from this patch.
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

There should be no functional change resulting from this patch.
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Move ide_map_sg() calls out from ide_build_sglist()
  to ide_dma_prepare().

* Pass command to ide_destroy_dmatable().

* Rename ide_build_sglist() to ide_dma_map_sg()
  and ide_destroy_dmatable() to ide_dma_unmap_sg().

There should be no functional changes caused by this patch.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Set/clear drive->waiting_for_dma flag in the core code
instead of in ->dma_setup and ->dma_end methods.

There should be no functional changes caused by this patch.
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Move ide_destroy_dmatable() call out from ->dma_end method to
{ide_pc,cdrom_newpc,ide_dma}_intr(), ide_dma_timeout_retry()
and sgiioc4_resetproc().

This causes minor/safe behavior changes w.r.t.:
* cmd64x.c::cmd64{8,x}_dma_end()
* cs5536.c::cs5536_dma_end()
* icside.c::icside_dma_end()
* it821x.c::it821x_dma_end()
* scc_pata.c::__scc_dma_end()
* sl82c105.c::sl82c105_dma_end()
* tx4939ide.c::tx4939ide_dma_end()

v2:
* Fix build for CONFIG_BLK_DEV_IDEDMA=n (reported by Randy Dunlap).

Cc: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Cache drive->queue in local variable and use max().

There should be no functional changes caused by this patch.
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Acked-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* 'thislen' is always <= cmd->nleft for non-fs requests so the transfer
  padding inside the 'while (thislen > 0)' loop can happen only for fs
  requests -- then move it out of the loop and unify with the transfer
  padding for non-fs requests ('thislen' == 'len' for fs requests).

* blk_dump_rq_flags() dumps all request flags so it is enough to pass
  only the function name to it.

* Update my Copyrights while at it.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Use the following facts:

- rq->nr_sectors should now be always equal to (non-zero)
  rq->hard_nr_sectors for fs requests

- REQ_TYPE_ATA_PC requests have never bio attached to them

- rq->hard_nr_sectors == 0 for REQ_TYPE_ATA_PC requests

- DMA is used only for fs, pc and REQ_TYPE_ATA_PC requests

- 'uptodate' is ignored for pc requests ('rc == 0' case)

and use the common completion path also for DMA requests.

There should be no functional changes caused by this patch

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Convert ide-cd to use scatterlists for PIO transfers and get rid of
partial completions (except on error) also for non-fs requests.

v2:
Do not map dataless commands to an sg since it oopses on the virt_to_page()
translation check when DEBUG_VIRTUAL is enabled.  (from Borislav Petkov,
reported/bisected-by Tetsuo Handa).

Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

There should be no functional changes caused by this patch.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

We now support arbitrary number of bytes per-IRQ also for fs requests
so remove ide_cd_check_transfer_size() and IDE_AFLAG_LIMIT_NFRAMES.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Export ide_pio_bytes().

* Add ->last_xfer_len field to struct ide_cmd.

* Add ide_cd_error_cmd() helper to ide-cd.

* Convert ide-cd to use scatterlists also for PIO transfers (fs requests
  only for now) and get rid of partial completions (except when the error
  happens -- which is still subject to change later because looking at
  ATAPI spec it seems that the device is free to error the whole transfer
  with setting the Error bit only on the last transfer chunk).

* Update ide_cd_{prepare_rw,restore_request,do_request}() accordingly.

* Inline ide_cd_restore_request() into cdrom_start_rw().

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

There should be no functional changes caused by this patch.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Untangling cdrom_end_request() uncovered an error in completing
failed requests in ide_cd_do_request().  Fix it.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Inline cdrom_end_request() into cdrom_newpc_intr()
and ide_cd_do_request().

There should be no functional changes caused by this patch.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Move cdrom_end_request() calls from cdrom_decode_status()
  and ide_cd_check_ireason() to cdrom_newpc_intr().

* Unify cdrom_newpc_intr() exit paths.

There should be no functional changes caused by this patch.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Move setting REQ_FAILED flag out from 'end_request' exit path in
cdrom_newpc_intr() and also rename 'end_request' to 'out_end'.

There should be no functional changes caused by this patch.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Move cdrom_end_request() calls from cdrom_start_rw()
  and ide_cd_prepare_rw_request() to ide_cd_do_request().

* Unify ide_cd_do_request() exit paths.

There should be no functional changes caused by this patch.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

There should be no functional changes caused by this patch.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

ide-scsi is gone...

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

It makes no sense to check for BSY bit being set as earlier OK_STAT()
check in cdrom_end_request() makes sure that BSY bit is cleared.

There should be no functional changes caused by this patch.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

There should be no functional changes caused by this patch.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Use ide_end_rq() also for failed non-fs requests on completion
of REQUEST SENSE requests + use blk_rq_bytes() while at it.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Set hwif->expiry prior to calling [__]ide_set_handler()
  and drop 'expiry' argument.

* Set hwif->expiry to NULL in ide_{timer_expiry,intr}()
  and remove 'hwif->expiry = NULL' assignments.

There should be no functional changes caused by this patch.
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Pass command to ide_issue_pc() and update ->do_request methods
  in ide-{cd,floppy,tape}.c accordingly.

* Convert ide_pktcmd_tf_load() to ide_init_packet_cmd() which
  just initializes command structure and use do_rw_taskfile()
  to load ATA_CMD_PACKET commands.

While at it:

* Rename ide{floppy,tape}_issue_pc() to ide_{floppy,tape}_issue_pc().

There should be no functional changes caused by this patch.
Acked-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Add ide_rq_bytes() helper.

* Add blk_noretry_request() quirk to ide_complete_rq() (currently only fs
  requests can be marked as "noretry" so there is no change in behavior).

* Switch current ide_end_request() users to use ide_complete_rq().

  [ No need to check for rq->nr_sectors == 0 in {ide_dma,task_pio}_intr(),
    nsectors == 0 in cdrom_end_request() and err == 0 in ide_do_devset(). ]

* Remove no longer needed ide_end_request().

There should be no functional changes caused by this patch.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Move rq->errors quirk out from ide_end_request() to its call sites.

There should be no functional changes caused by this patch.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Move 'uptodate' quirk from ide_end_rq() to its users.

* Move quirks for blk_noretry_request() and !blk_fs_request()
  requests from ide_end_rq() to ide_end_request().

There should be no functional changes caused by this patch.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Move request dequeuing from __ide_end_request() to ide_end_request().

* Rename __ide_end_request() to ide_end_rq() and export it.

* Fix ide_end_rq() to pass original blk_end_request() return value.

* ide_end_dequeued_request() is used only in cdrom_end_request()
  so inline it there and then remove the function.

v2:
* Remove needless BUG_ON() while at it (start_request()'s one is enough).

There should be no functional changes caused by this patch.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Handle completion of private driver requests explicitly
  for ide_floppy and ide_tape media in ide_kill_rq().

* Remove no longer needed ->end_request method.

There should be no functional changes caused by this patch.
Acked-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

There should be no functionality change resulting from this patch.
Suggested-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>