Bind DMA handle fails with Solaris 10 x86

Question

Our device driver and device uses no scatter gather and
we have always set the sgllen filed of the DMA_ATTR to 1.
Even so, ddi_dma_buf_bind_handle() would often result in
more than one dma cookie for a transfer on most x86 systems.
We handle this in the device driver, starting a new transfer from
the device for each cookie.
Along comes Solaris 10 and ddi_dma_buf_bind_handle() fails with a
DDI_DMA_TOOBIG error for all DMA transfer over 1200 bytes or so.
We are not sure what changed in Solaris 10 to cause our method to
no longer work.
Is the correct thing to simply set the sgllen field to -1?

Answer 1

Following up on my previous post ....
Setting the dma_attr_sgllen field of the DMA_ATTR to -1
does seem to solve the problem for Solaris 10. It works
on sparc v9, intel32 and amd64 platforms.
However, it does not work with Solaris 9 on x86 platforms.
In this case, ddi_dma_buf_bind_handle() fails with a
DDI_DMA_BADATTR error.
On sparc platforms it does not seem to matter. A value of
either 1 or -1 works for both Solaris 9 and 10.
In order to maintain backwards compatibility, we will need to
make use of autoconf variables, having our conifgure script
substitute an appropriate value for the dma_attr_sgllen
based on the host operating system version.