Petr Vandrovec wrote:
Hello,
maybe I should have trusted SiliconImage... But, well, it is not true that
you cannot use PMP with Sil 3512 and 3114. You can, if you try hard enough.
Patch below tries hard enough ;-) Unfortunately it has few drawbacks:
(1) Hardware ignores PMP field in received frames, so when D2H FIS arrives
from device not selected, you have last chance to record what's current
device state.
(2) When NIEN bit is set on device, every interrupt source seems to be
disabled. Not good when interlocked FIS arrives while bus is resetted,
which happens almost always...
(3) And due to all this interrupts are always left enabled on the device,
and driver just tries to provide some more compatible view to remaining
parts of libata.
Driver as is below works with Sil 3726 port multiplier with couple devices
attached. I did not test it without port multiplier (I think it will
break) as card I have has only eSATA ports and I currently do not
have eSATA non-PMP enclosure around.
So patch is definitely not intended for merge, and most probably it would
have to be separate driver anyway as I have some doubts about compatibility
between interrupts being always enabled and various ATI clones. So this
is more or less just FYI, unless you believe that it is possible to get
this patch to some mergeable shape. I have some doubts, so I've ordered
3124 based card. Maybe I should have done that week ago...
On other side driver works with PMP as well as AHCI driver (i.e. full
SDB_NOTIFY support, but command based switching and no NCQ - I think I
could implement NCQ if I would try hard enough via interlocked FIS, but
it does not look like worth of effort).
Anyway, here it goes. Good night.
Quite impressive, I must say :)
It is similar to how NCQ is implemented in sata_nv ('SW NCQ'), and how I
am contemplating support for ATAPI on a few controllers that do not
support it.
With regards to interrupts, sata_sil provides hardware registers to mask
and monitor the interrupt condition, so I don't see much danger in
interrupts always being enabled. EH will need to mess with interrupt
delivery on a per-port granularity, but that's probably about it.
Jeff
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