lkml.org 
[lkml]   [2006]   [Oct]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC PATCH] nForce4 ADMA with NCQ: It's aliiiive..
Mark Lord wrote:
> Robert Hancock wrote:
>>
>> I also noticed that I'm still using the default 64KB libata
>> dma_boundary value, this should be 4GB for ADMA mode (but fixed up
>> back to the default if an ATAPI device is connected, same as with the
>> DMA mask).
>
> Be careful of that. The original PDC hardware for ADMA still had
> the "don't cross a 64KB boundary" requirement.
>
> Cheers

That is part of the ADMA spec - but in that case, how come the
pdc_adma.c driver sets the dma_boundary in the SCSI host template to
4GB? That seems wrong.

In any case, however, I really doubt the NVIDIA ADMA controller shares
this limitation - they provide 32 bits for the region length (standard
ADMA only has 16 bits), which wouldn't be very useful if you couldn't
cross a 64KB boundary..

--
Robert Hancock Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-10-17 01:43    [W:0.097 / U:0.268 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site