litmus-rt-ext-res.git/drivers/scsi/arm, branch EXT-RES

scsi: rename SCSI_MAX_{SG, SG_CHAIN}_SEGMENTS

2016-04-15T20:53:14+00:00

Rename SCSI_MAX_SG_SEGMENTS to SG_CHUNK_SIZE, which means the amount
we fit into a single scatterlist chunk.

Rename SCSI_MAX_SG_CHAIN_SEGMENTS to SG_MAX_SEGMENTS.

Will move these 2 generic definitions to scatterlist.h later.

Reviewed-by: Christoph Hellwig 
Acked-by: Bart Van Assche  (for ib_srp changes)
Signed-off-by: Ming Lin 
Acked-by: Tejun Heo 
Reviewed-by: Sagi Grimberg 
Signed-off-by: Martin K. Petersen

ncr5380: Remove DONT_USE_INTR and AUTOPROBE_IRQ macros

2016-04-11T20:57:09+00:00

Signed-off-by: Finn Thain 
Reviewed-by: Hannes Reinecke 
Tested-by: Michael Schmitz 
Tested-by: Ondrej Zary 
Signed-off-by: Martin K. Petersen

ncr5380: Merge DMA implementation from atari_NCR5380 core driver

2016-04-11T20:57:09+00:00

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 
Reviewed-by: Hannes Reinecke 
Tested-by: Michael Schmitz 
Tested-by: Ondrej Zary 
Signed-off-by: Martin K. Petersen

ncr5380: Adopt uniform DMA setup convention

2016-04-11T20:57:09+00:00

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 
Reviewed-by: Hannes Reinecke 
Tested-by: Michael Schmitz 
Tested-by: Ondrej Zary 
Signed-off-by: Martin K. Petersen

ncr5380: Use DMA hooks for PDMA

2016-04-11T20:57:09+00:00

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 
Reviewed-by: Hannes Reinecke 
Tested-by: Michael Schmitz 
Tested-by: Ondrej Zary 
Signed-off-by: Martin K. Petersen

ncr5380: Remove PSEUDO_DMA macro

2016-04-11T20:57:09+00:00

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 
Reviewed-by: Hannes Reinecke 
Tested-by: Michael Schmitz 
Tested-by: Ondrej Zary 
Signed-off-by: Martin K. Petersen

ncr5380: Disable the DMA errata workaround flag by default

2016-04-11T20:57:09+00:00

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 
Reviewed-by: Hannes Reinecke 
Tested-by: Michael Schmitz 
Tested-by: Ondrej Zary 
Signed-off-by: Martin K. Petersen

scsi: fas216: avoid fas216_log_setup for loadable module

2016-02-24T02:27:02+00:00

We get a warning for the fas216 driver when it is compiled as a loadable
module, as the __setup() functions are never called then:

scsi/arm/fas216.c:101:19: warning: 'fas216_log_setup' defined but not used [-Wunused-function]
 static int __init fas216_log_setup(char *str)

This adds an #ifndef MODULE around the definition to shut up the warning
and clarify for the reader when it is used or not.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Martin K. Petersen

scsi: acornscsi: mark calc_sync_xfer as __maybe_unused

2016-02-24T02:27:02+00:00

The calc_sync_xfer function is only used if CONFIG_SCSI_ACORNSCSI_SYNC
is set, otherwise we get a compiler warning:

scsi/arm/acornscsi.c:680:15: warning: 'calc_sync_xfer' defined but not used [-Wunused-function]
 unsigned char calc_sync_xfer(unsigned int period, unsigned int offset)

This marks the function as __maybe_unused to shut up the warning and
silently drop the function in the object code when there is no caller.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Martin K. Petersen

ncr5380: Fix soft lockups

2016-01-07T02:43:09+00:00

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 
Reviewed-by: Hannes Reinecke 
Tested-by: Ondrej Zary 
Tested-by: Michael Schmitz 
Signed-off-by: Martin K. Petersen