The am53c974 has an design issue where a single byte might be
left in the SCSI FIFO after a DMA transfer.
As the handling code is currently untested add a WARN_ON()
statement here.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Using DMA for command submission has the drawback that it might
generate additional DMA completion interrupts after the command
has been submitted to the device.
Additionally the am53c974 has a design flaw causing it
to generate spurious interrupts even though DMA completion
interrupts are not enabled.
This can be avoided by using the FIFO for command submission.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Add a field 'num_tags' to the esp structure to allow drivers
to overwrite the number of avialable tags if required.
Default is ESP_DEFAULT_TAGS.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Meelis Roos reports a crash in esp_free_lun_tag() in the presense
of a disk which has died.
The issue is that when we issue an autosense command, we do so by
hijacking the original command that caused the check-condition.
When we do so we clear out the ent->tag[] array when we issue it via
find_and_prep_issuable_command(). This is so that the autosense
command is forced to be issued non-tagged.
That is problematic, because it is the value of ent->tag[] which
determines whether we issued the original scsi command as tagged
vs. non-tagged (see esp_alloc_lun_tag()).
And that, in turn, is what trips up the sanity checks in
esp_free_lun_tag(). That function needs the original ->tag[] values
in order to free up the tag slot properly.
Fix this by remembering the original command's tag values, and
having esp_alloc_lun_tag() and esp_free_lun_tag() use them.
Reported-by: Meelis Roos <mroos@linux.ee>
Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>
This thing was completely pointless.
Just find the OF device in the parent of drivers that want to program
this device, and map the DMA regs inside such drivers too.
This also moves the dummy claim_dma_lock() and release_dma_lock()
implementation to floppy_32.h, which makes it handle this issue
just like floppy_64.h does.
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace the mac_esp driver with a new one based on the esp_scsi core.
For esp_scsi: add support for sync transfers for the PIO mode, add a new
esp_driver_ops method to get the maximum dma transfer size (like the old
NCR53C9x driver), and some cleanups.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Many of the overflow checks test whether the value has
gone negative, and we want to retain such checks.
Reported by Julia Lawall.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This reverts d73f5222a6
The bug that made us increase ESP_BUS_TIMEOUT to 275 turned out to be
a memset bug on 32-bit sparc.
It is better to put this back at the correct timeout value than to
leave it increased when there is no reason for doing so.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This matches the original driver's value and seems to be
necessary for some disks on sun4c systems.
Reported by Mark Fortescue <mark@mtfhpc.demon.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Major features:
1) Tagged queuing support.
2) Will properly negotiate for synchronous transfers even on
devices that reject the wide negotiation message, such as
CDROMs
3) Significantly lower kernel stack usage in interrupt
handler path by elimination of function vector arrays,
replaced by a top-level switch statement state machine.
4) Uses generic scsi infrastructure as much as possible to
avoid code duplication.
5) Automatic request of sense data in response to CHECK_CONDITION
6) Portable to other platforms using ESP such as DEC and Sun3
systems.
Signed-off-by: David S. Miller <davem@davemloft.net>
Hannes Reinecke