Subject: Re: bus_dmamap_sync() in ti(4) or the lack thereof
To: None <email@example.com>
From: Izumi Tsutsui <firstname.lastname@example.org>
Date: 02/28/2007 08:35:04
> ti(4) doesn't work right on sparc64. With DIAGNOSTIC i get tons
> of "iommu_dvmamap_load: map still in use".
This is usually caused by missing bus_dmamap_unload(9).
(IMHO other ports should have the similar assersions)
> I took a glance at the ti(4) code and noticed the absence of any
> preread/postread dma syncs, despite the fact that the driver relies
> heavily on reuse of dma maps. This can't be right, can it?
It should have proper sync calls otherwise it won't work on
non DMA coherent architecture (like sgimips O2) or architectures
which require bounce buffer (like some alpha), but many FreeBSD's
drivers often lack them since they are not required by "major" ports ;-p
> The fact that the driver appears to reload maps without unloading
> them first might be caused by something else, though.
It seems bus_dmamap_unload(9) is needed before calling ti_newbuf_jumbo()
or ti_newbuf_mini() in ti_rxeof().