Large PIO transfers are broken up into chunks to try to avoid disabling
local IRQs for long periods. But IRQs are still disabled for too long
and this causes SCC FIFO overruns during serial port transfers.
This patch reduces the PIO chunk size to reduce interrupt latency to
something on the order of milliseconds, at the expense of additional CPU
overhead from extra iterations of the NCR5380_main() loop.
That CPU overhead is a problem for slow machines (e.g. mac_scsi on 25
MHz 68030) but these machines generally use PDMA not PIO. This patch
doesn't make the overhead any worse on my Mac LC III (because it only
gets about 510 accesses per ms).
This patch decreases disk performance by a fraction of one percent for
dmx3191d on my 333 MHz PowerPC 750. Other affected hardware (such as
g_NCR5380 on x86) was not tested but 5380 ISA cards generally use PDMA
and not PIO.
[mkp: fix whitespace]
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
With commit 3a0f64bfa9 ("mac_scsi: Fix pseudo DMA implementation")
some versions of gcc now warn:
In file included from drivers/scsi/mac_scsi.c:335:
drivers/scsi/NCR5380.h:295: warning: `NCR5380_poll_politely' declared inline after being called
drivers/scsi/NCR5380.h:295: warning: previous declaration of `NCR5380_poll_politely' was here
Avoid this by defining NCR5380_poll_politely() in NCR5380.h.
[mkp: checkpatch warnings]
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
I'm told that some targets are liable to disconnect a REQUEST SENSE
command. Theoretically this would cause a command undergoing autosense to
be moved onto the disconnected list. The bus reset handler must call
complete_cmd() for these commands, otherwise the hostdata->sensing pointer
will not get cleared. That would cause autosense processing to stall and
a timeout or an incorrect scsi_eh_restore_cmnd() would eventually follow.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reported-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Decode all bits in the chip registers. They are all useful at times.
Fix printk severity so that this output can be suppressed along with
the other debugging output.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The driver has a limit of eight LUs because of the byte-sized bitfield
that is used for busy flags. That means the maximum LUN is 7. The default
is 8.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Now that atari_scsi and sun3_scsi have been converted to use the NCR5380.c
core driver, remove atari_NCR5380.c. Also remove the last vestiges of its
Tagged Command Queueing implementation from the wrapper drivers.
The TCQ support in atari_NCR5380.c is abandoned by this patch. It is not
merged into the remaining core driver because,
1) atari_scsi defines SUPPORT_TAGS but leaves FLAG_TAGGED_QUEUING disabled
by default, which indicates that it is mostly undesirable.
2) I'm told that it doesn't work correctly when enabled.
3) The algorithm does not make use of block layer tags which it will have
to do because scmd->tag is deprecated.
4) sun3_scsi doesn't define SUPPORT_TAGS at all, yet the the SUPPORT_TAGS
macro interacts with the CONFIG_SUN3 macro in 'interesting' ways.
5) Compile-time configuration with macros like SUPPORT_TAGS caused the
configuration space to explode, leading to untestable and unmaintainable
code that is too hard to reason about.
The merge_contiguous_buffers() code is also abandoned. This was unused
by sun3_scsi. Only atari_scsi used it and then only on TT, because only TT
supports scatter/gather. I suspect that the TT would work fine with
ENABLE_CLUSTERING instead. If someone can benchmark the difference then
perhaps the merge_contiguous_buffers() code can be be justified. Until
then we are better off without the extra complexity.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Add support for the custom Sun 3 DMA logic to the NCR5380.c core driver.
This code is copied from atari_NCR5380.c.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Add support for the Atari ST DMA chip to the NCR5380.c core driver.
This code is copied from atari_NCR5380.c.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Adopt the DMA implementation from atari_NCR5380.c. This means that
atari_scsi and sun3_scsi can make use of the NCR5380.c core driver
and the atari_NCR5380.c driver fork can be made redundant.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Standardize the DMA setup hooks so that the DMA implementation in
atari_NCR5380.c can be reconciled with pseudo DMA implementation in
NCR5380.c.
Calls to NCR5380_dma_recv_setup() and NCR5380_dma_send_setup() return
a negative value on failure, zero on PDMA transfer success and a positive
byte count for DMA setup success.
This convention is not entirely new, but is now applied consistently.
Also remove a pointless Status Register access: the *phase assignment is
redundant because after NCR5380_transfer_dma() returns control to
NCR5380_information_transfer(), that routine then returns control
to NCR5380_main(), which means *phase is dead.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Those wrapper drivers which use DMA define the REAL_DMA macro and
those which use pseudo DMA define PSEUDO_DMA. These macros need to be
removed for a number of reasons, not least of which is to have drivers
share more code.
Redefine the PDMA send and receive hooks as DMA setup hooks, so that the
DMA code can be shared by all 5380 wrapper drivers. This will help to
reunify the forked core driver.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The io_recovery_delay macro is intended to insert a microsecond delay
between the chip register accesses that begin a DMA operation. This
is reportedly needed for some ISA boards.
Reverse the sense of the macro test so that in the common case,
where no delay is required, drivers need not define the macro.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
For those wrapper drivers which only implement Programmed IO, have
NCR5380_dma_xfer_len() evaluate to zero. That allows PDMA to be easily
disabled at run-time and so the PSEUDO_DMA macro is no longer needed.
Also remove the spin counters used for debugging pseudo DMA drivers.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The only chip that needs the workarounds enabled is an early NMOS
device. That means that the common case is to disable them.
Unfortunately the sense of the flag is such that it has to be set
for the common case.
Rename the flag so that zero can be used to mean "no errata workarounds
needed". This simplifies the code.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
For the NCR5380.c core driver, these macros are never used.
If REAL_DMA were to be defined, compilation would fail.
For the atari_NCR5380.c core driver, REAL_DMA is always defined.
Hence these macros are pointless.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Drivers that define PSEUDO_DMA also define NCR5380_dma_xfer_len.
The core driver must call NCR5380_dma_xfer_len which means
FLAG_NO_PSEUDO_DMA can be eradicated from the core driver.
dmx3191d doesn't define PSEUDO_DMA and has no use for FLAG_NO_PSEUDO_DMA,
so remove it there also.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This bug causes the wrong command to have its sense pointer overwritten,
which sometimes leads to a NULL pointer deref. Fix this by checking which
command is being requeued before restoring the scsi_eh_save data.
It turns out that some targets will disconnect a REQUEST SENSE command.
The autosense algorithm doesn't anticipate this. Hence multiple commands
can end up undergoing autosense simultaneously, and they will all try to
use the same scsi_eh_save struct, which won't work. Defer autosense when
the scsi_eh_save storage is in use by another command.
Fixes: f27db8eb98 ("ncr5380: Fix autosense bugs")
Reported-and-tested-by: Michael Schmitz <schmitzmic@gmail.com>
Cc: <stable@vger.kernel.org> # 4.5
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Add missing checks for EH abort during arbitration and selection.
Rework the handling of NCR5380_select() result to improve clarity.
Fixes: 707d62b37f ("ncr5380: Fix EH during arbitration and selection")
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Cc: <stable@vger.kernel.org> # 4.5
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The list structures and related logic used in the NCR5380 driver mean that
a command cannot be queued twice (i.e. can't appear on more than one queue
and can't appear on the same queue more than once).
The abort handler must forget the command so that the mid-layer can re-use
it. E.g. the ML may send it back to the LLD via via scsi_eh_get_sense().
Fix this and also fix two error paths, so that commands get forgotten iff
completed.
Fixes: 8b00c3d5d4 ("ncr5380: Implement new eh_abort_handler")
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Cc: <stable@vger.kernel.org> # 4.5
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Calling NCR5380_select() from the abort handler causes various problems.
Firstly, it means potentially re-entering NCR5380_select(). Secondly, it
means that the lock is released, which permits the EH handlers to be
re-entered. The combination results in crashes. Don't do it.
Fixes: 8b00c3d5d4 ("ncr5380: Implement new eh_abort_handler")
Reported-and-tested-by: Michael Schmitz <schmitzmic@gmail.com>
Cc: <stable@vger.kernel.org> # 4.5
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The calls to NCR5380_transfer_pio() for DATA IN and DATA OUT phases will
modify cmd->SCp.this_residual, cmd->SCp.ptr and cmd->SCp.buffer. That
works as long as EH does not intervene, which became possible in
atari_NCR5380.c when I changed the locking to bring it closer to
NCR5380.c.
If error recovery aborts the command, the scsi_cmnd in question and its
buffer will be returned to the mid-layer. So the transfer has to cease,
but it can't be stopped by the initiator because the target controls the
bus phase.
The problem does not arise if the lock is not released. That was fine for
atari_scsi, because it implements DMA. For the other drivers, we have to
release the lock and re-enable interrupts for long PIO data transfers.
The solution is to split the transfer into small chunks. In between chunks
the main loop releases the lock and re-enables interrupts. Thus interrupts
can be serviced and eh_bus_reset_handler can intervene if need be.
This fixes an oops in NCR5380_transfer_pio() that can happen when the EH
abort handler is invoked during DATA IN or DATA OUT phase.
Fixes: 11d2f63b9c ("ncr5380: Change instance->host_lock to hostdata->lock")
Reported-and-tested-by: Michael Schmitz <schmitzmic@gmail.com>
Cc: <stable@vger.kernel.org> # 4.5
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Commands subject to exception handling are to be returned to the scsi
mid-layer. Make sure that the various command pointers and command lists
in the low-level driver are correctly cleansed of affected commands.
This fixes some bugs that I accidentally introduced in v4.5-rc1 including
the removal of INIT_LIST_HEAD for the 'autosense' and 'disconnected'
command lists, and the possible NULL pointer dereference in
NCR5380_bus_reset() that was reported by Dan Carpenter.
hostdata->sensing may also point to an affected command so this pointer
also has to be cleared. The abort handler calls complete_cmd() to take
care of this; let's have the bus reset handler do the same.
The issue queue may also contain an affected command. If so, remove it.
This also follows the abort handler logic.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 62717f537e ("ncr5380: Implement new eh_bus_reset_handler")
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Cc: <stable@vger.kernel.org> # 4.5
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
In the past, NCR5380.c was overlooked by those working on atari_NCR5380.c
and this caused needless divergence. All of the changes in this patch were
taken from atari_NCR5380.c.
This removes some unimportant discrepancies between the two core driver
forks so that 'diff' can be used to reveal the important ones, to
facilitate reunification.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Hanging indentation was a poor choice for the text inside comments. It
has been used in the wrong places and done badly elsewhere. There is
little consistency within any file. One fork of the core driver uses
tabs for this indentation while the other uses spaces. Better to use
flush-left alignment throughout.
This patch is the result of the following substitution. It replaces tabs
and spaces at the start of a comment line with a single space.
perl -i -pe 's,^(\t*[/ ]\*)[ \t]+,$1 ,' drivers/scsi/{atari_,}NCR5380.c
This removes some unimportant discrepancies between the two core driver
forks so that the important ones become obvious, to facilitate
reunification.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This patch is the result of the following substitution. It removes any
tabs and spaces at the end of a line.
perl -i -pe 's,[\t ]+$,,' drivers/scsi/{atari_,}NCR5380.c
This removes some unimportant discrepancies between the two core driver
forks so that the important ones become obvious, to facilitate
reunification.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The CVS revision log is not nearly as useful as the history/history.git
repo, so remove it. Roman's commentary at the top of his driver repeats
the same information elsewhere in the file so remove it. Also remove
some other redundant or obsolete comments.
Both the driver and the datasheets confusingly refer to a DMA access
for a SCSI WRITE command as a "DMA write". Similarly a SCSI READ command
is called a "DMA read". This is the opposite of the usual convention.
Thankfully, the chip documentation and driver code also use "DMA send" and
"DMA receive", so adopt this terminology.
This removes some unimportant discrepancies between the two core driver
forks so that 'diff' can be used to reveal the important ones, to
facilitate reunification.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Because of the rudimentary design of the chip, it is necessary to poll the
SCSI bus signals during PIO and this tends to hog the CPU. The driver will
accept new commands while others execute, and this causes a soft lockup
because the workqueue item will not terminate until the issue queue is
emptied.
When exercising dmx3191d using sequential IO from dd, the driver is sent
512 KiB WRITE commands and 128 KiB READs. For a PIO transfer, the rate is
is only about 300 KiB/s, so these are long-running commands. And although
PDMA may run at several MiB/s, interrupts are disabled for the duration
of the transfer.
Fix the unresponsiveness and soft lockup issues by calling cond_resched()
after each command is completed and by limiting max_sectors for drivers
that don't implement real DMA.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Keep the two core driver forks in sync.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Remove the HOSTNO macro that is peculiar to atari_NCR5380.c and
contributes to the problem of divergence of the NCR5380 core drivers.
Keep NCR5380.c in sync.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
NCR5380.c lacks a sane eh_bus_reset_handler. The atari_NCR5380.c code is
much better but it should not throw out the issue queue (that would be
a host reset) and it neglects to set the result code for commands that it
throws out. Fix these bugs and keep the two core drivers in sync.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
During arbitration and selection, the relevant command is invisible to
exception handlers and can be found only in a pointer on the stack of a
different thread.
When eh_abort_handler can't find a given command, it can't decide whether
that command was completed already or is still in arbitration or selection
phase. But it must return either SUCCESS (e.g. command completed earlier)
or FAILED (could not abort the nexus, try bus reset).
The solution is to make sure all commands belonging to the LLD are always
visible to exception handlers. Add another scsi_cmnd pointer to the
hostdata struct to track the command in arbitration or selection phase.
Replace 'retain_dma_irq' with the new 'selecting' pointer, to bring
atari_NCR5380.c into line with NCR5380.c.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Introduce a new eh_abort_handler implementation. This one attempts to
follow all of the rules relating to EH handlers. There is still a known
bug: during selection, a command becomes invisible to the EH handlers
because it only appears in a pointer on the stack of a different thread.
This bug is addressed in a subsequent patch.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
NCR5380_information_transfer() may re-queue a command for autosense,
after calling scsi_eh_prep_cmnd(). This creates several possibilities:
1. Reselection may intervene before the re-queued command gets processed.
If the reconnected command then undergoes autosense, this causes the
scsi_eh_save data from the previous command to be overwritten.
2. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(),
a new REQUEST SENSE command may arrive. This would be queued ahead
of any command already undergoing autosense, which means the
scsi_eh_save data might be restored to the wrong command.
3. After NCR5380_information_transfer() calls scsi_eh_prep_cmnd(),
eh_abort_handler() may abort the command. But the scsi_eh_save data is
not discarded, which means the scsi_eh_save data might be incorrectly
restored to the next REQUEST SENSE command issued.
This patch adds a new autosense list so that commands that are re-queued
because of a CHECK CONDITION result can be kept apart from the REQUEST
SENSE commands that arrive via queuecommand.
This patch also adds a function dedicated to dequeueing and preparing the
next command for processing. By refactoring the main loop in this way,
scsi_eh_save takes place when an autosense command is dequeued rather
than when re-queued.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Implement a 'complete_cmd' function to complete commands. This is needed
by the following patch; the new function provides a site for the logic
needed to correctly handle REQUEST SENSE commands.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The NCR5380 drivers have a home-spun linked list implementation for
scsi_cmnd structs that uses cmd->host_scribble as a 'next' pointer. Adopt
the standard list_head data structure and list operations instead. Remove
the eh_abort_handler rather than convert it. Doing the conversion would
only be churn because the existing EH handlers don't work and get replaced
in a subsequent patch.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Printing command pointers can be useful when debugging queues. Other than
that, the LIST and REMOVE macros are just clutter. These macros are
redundant now that NDEBUG_QUEUES causes pointers to be printed, so remove
them.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Print the command pointers in the log messages for debugging queue data
structures. The LIST and REMOVE macros can then be removed.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Make use of the shost_priv() helper. Remove HOSTDATA and SETUP_HOSTDATA
macros because they harm readability.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Replace all H_NO and some HOSTNO macros (both peculiar to atari_NCR5380.c)
with a new dsprintk macro that's more useful and more consistent. The new
macro avoids a lot of boilerplate in new code in subsequent patches. Keep
NCR5380.c in sync. Remaining HOSTNO macros are removed as side-effects
of subsequent patches.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Some NCR5380 hosts offer a .show_info method to access the contents of
the various command list data structures from a procfs file. When NDEBUG
is set, the same information is sent to the console during EH.
The two core drivers, atari_NCR5380.c and NCR5380.c differ here. Because
it is just for debugging, the easiest way to fix the discrepancy is
simply remove this code.
The only remaining users of NCR5380_show_info() and NCR5380_write_info()
are drivers that define PSEUDO_DMA. The others have no use for the
.show_info method, so don't initialize it.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
NCR5380.c presently uses the instance->host_lock spin lock. Convert this
to a new spin lock that protects the NCR5380_hostdata struct.
atari_NCR5380.c previously used local_irq_save/restore() rather than a
spin lock. Convert this to hostdata->lock in irq mode. For SMP platforms,
the interrupt handler now also acquires the spin lock.
This brings all locking in the two core drivers into agreement.
Adding this locking also means that a bunch of volatile qualifiers can be
removed from the members of the NCR5380_hostdata struct. This is done in
a subsequent patch.
Proper locking will allow the abort handler to locate a command being
aborted. This is presently impossible if the abort handler is invoked when
the command has been moved from a queue to a pointer on the stack. (If
eh_abort_handler can't determine whether a command has been completed
or is still being processed then it can't decide whether to return
success or failure.)
The hostdata spin lock is now held when calling NCR5380_select() and
NCR5380_information_transfer(). Where possible, the lock is dropped for
polling and PIO transfers.
Clean up the now-redundant SELECT_ENABLE_REG writes, that used to provide
limited mutual exclusion between information_transfer() and reselect().
Accessing hostdata->connected without data races means taking the lock;
cleanup these accesses.
The new spin lock falls away for m68k and other UP builds, so this should
have little impact there. In the SMP case the new lock should be
uncontested even when the SCSI bus is contested.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Remove FLAG_DTC3181E. It was used to suppress a final Arbitration Lost
(SEL asserted) test that isn't actually needed. The test was suppressed
because it causes problems for DTC436 and DTC536 chips. It takes place
after the host wins arbitration, so SEL has been asserted. These chips
can't seem to tell whether it was the host or another bus device that
did so.
This questionable final test appears in a flow chart in an early NCR5380
datasheet. It was removed from later documents like the DP5380 datasheet.
By the time this final test takes place, the driver has already tested
the Arbitration Lost bit several times. The first test happens 3 us after
BUS FREE (or longer due to register access delays). The protocol requires
that a device stop signalling within 1.8 us after BUS FREE unless it won
arbitration, in which case it must assert SEL, which is detected 1.2 us
later by the first Arbitration Lost test.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
NDEBUG_NO_DATAOUT should not disable DATA IN phases too. Fix this.
(This bug has long been fixed in atari_NCR5380.c.)
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Remove unused includes (stat.h, signal.h, proc_fs.h) and move includes
needed by the core drivers into the common header (delay.h etc).
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Fix the array bounds check when transferring an extended message from the
target.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Bring the two NCR5380_reselect() implementations into agreement.
Replace infinite loops in atari_NCR5380.c with timeouts, as per NCR5380.c.
Remove 'abort' flag in NCR5380.c as per atari_NCR5380.c -- if reselection
fails, there may be no MESSAGE IN phase so don't attempt data transfer.
During selection, don't interfere with the chip registers after a
reselection interrupt intervenes.
Clean up some trivial issues with code style, comments and printk.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
The workarounds for chip errata appear twice, in slightly different
forms. One is used when defined(REAL_DMA) || defined(REAL_DMA_POLL), the
other when defined(PSEUDO_DMA). In the PDMA case, the workarounds have
been made conditional on FLAG_NO_DMA_FIXUPS. Do the same for the DMA case,
to eliminate the READ_OVERRUNS macro.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Finn Thain