Scatter-gather list constraints

From: Alan Stern
Date: Fri Jun 20 2008 - 16:45:43 EST


Is there any way to express the constraint that for a particular
request queue, all members of a scatter-gather list (except the last)
must be a multiple of a particular length?

This question arises in connection with wireless USB mass-storage
devices. The controller driver requires that all DMA segments
in a transfer, other than the last one, have a multiple of 1024 bytes.
But we're sometimes getting s-g lists where an element contains an odd
number of 512-byte sectors, and of course it doesn't work.

Thanks,

Alan Stern

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