kernel/git/stable/linux.git/drivers/scsi/atari_NCR5380.c, branch master

ncr5380: Remove disused atari_NCR5380.c core driver

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

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

atari_NCR5380: Remove DMA_MIN_SIZE macro

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

Only the atari_scsi and sun3_scsi drivers define DMA_MIN_SIZE. Both drivers also define NCR5380_dma_xfer_len, which means DMA_MIN_SIZE can be removed from the core driver. This removes another discrepancy between the two core drivers. Signed-off-by: Finn Thain Tested-by: Michael Schmitz Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen

ncr5380: Remove REAL_DMA and REAL_DMA_POLL macros

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

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

ncr5380: Call scsi_eh_prep_cmnd() and scsi_eh_restore_cmnd() as and when appropriate

2016-03-01T14:38:58+00:00

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: f27db8eb98a1 ("ncr5380: Fix autosense bugs") Reported-and-tested-by: Michael Schmitz Cc: # 4.5 Signed-off-by: Finn Thain Signed-off-by: Martin K. Petersen

ncr5380: Fix NCR5380_select() EH checks and result handling

2016-03-01T14:38:50+00:00

Add missing checks for EH abort during arbitration and selection. Rework the handling of NCR5380_select() result to improve clarity. Fixes: 707d62b37fbb ("ncr5380: Fix EH during arbitration and selection") Tested-by: Michael Schmitz Cc: # 4.5 Signed-off-by: Finn Thain Signed-off-by: Martin K. Petersen

ncr5380: Forget aborted commands

2016-03-01T14:38:25+00:00

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: 8b00c3d5d40d ("ncr5380: Implement new eh_abort_handler") Tested-by: Michael Schmitz Cc: # 4.5 Signed-off-by: Finn Thain Signed-off-by: Martin K. Petersen

ncr5380: Dont re-enter NCR5380_select()

2016-03-01T14:38:14+00:00

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: 8b00c3d5d40d ("ncr5380: Implement new eh_abort_handler") Reported-and-tested-by: Michael Schmitz Cc: # 4.5 Signed-off-by: Finn Thain Signed-off-by: Martin K. Petersen

ncr5380: Dont release lock for PIO transfer

2016-03-01T14:37:53+00:00

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: 11d2f63b9cf5 ("ncr5380: Change instance->host_lock to hostdata->lock") Reported-and-tested-by: Michael Schmitz Cc: # 4.5 Signed-off-by: Finn Thain Signed-off-by: Martin K. Petersen

ncr5380: Correctly clear command pointers and lists after bus reset

2016-03-01T14:37:11+00:00

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 Fixes: 62717f537e1b ("ncr5380: Implement new eh_bus_reset_handler") Tested-by: Michael Schmitz Cc: # 4.5 Signed-off-by: Finn Thain Signed-off-by: Martin K. Petersen

ncr5380: Cleanup whitespace and parentheses

2016-01-07T02:43:10+00:00

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