On Wed, Sep 03, 2008 at 03:33:55PM -0400, Eduardo Valentin wrote:
> Hi,
>
> On Wed, Sep 3, 2008 at 2:48 PM, Russell King <rmk@xxxxxxxxxxxxxxxx> wrote:
> > On Wed, Sep 03, 2008 at 11:33:51AM -0400, Eduardo Valentin wrote:
> >> > @@ -159,7 +159,7 @@ static struct omap_mcbsp_platform_data omap730_mcbsp_pdata[] = {
> >> > #ifdef CONFIG_ARCH_OMAP15XX
> >> > static struct omap_mcbsp_platform_data omap15xx_mcbsp_pdata[] = {
> >> > {
> >> > - .virt_base = OMAP1510_MCBSP1_BASE,
> >> > + .virt_base = OMAP1510_MCBSP1_BASE, /* FIXME: virtual or physical */
> >> AFAIK, OMAP1510_MCBSP1_BASE is physical. So, I'd say:
> >> + .virt_base = IO_ADDRESS(OMAP1510_MCBSP1_BASE),
> >>
> >> Because, plat-omap/mcbsp.c expect .virt_base to be a virtual address.
> >
> > Ok, I'll fix these which you've confirmed in my version for mainline.
> >
> >> > @@ -701,6 +702,7 @@ int omap_mcbsp_xmit_buffer(unsigned int id, dma_addr_t buffer,
> >> > omap_set_dma_dest_params(mcbsp->dma_tx_lch,
> >> > src_port,
> >> > OMAP_DMA_AMODE_CONSTANT,
> >> > + /* FIXME: this is a virtual address */
> >> > mcbsp->io_base + OMAP_MCBSP_REG_DXR1,
> >>
> >> yes, that's true. This is expected to be virtual (mcbsp->io_base).
> >
> > Don't you mean that it is expected to be physical?
> >
>
> Well, correct me if I'm wrong, but I meant that the result of
> mcbsp->io_base + OMAP_MCBSP_REG_DXR1
>
> is supposed to be virtual.
Yes, that will be virtual. But what does it mean to call:
omap_set_dma_dest_params()
specifying a virtual address? Can the DMA controller cope with DMAing
to virtual addresses? My hunch is that the DMA controller can't cope
with that, so giving it a virtual address is a bug.
Let me change the question: does omap_set_dma_dest_params()'s 4th
argument take a virtual or a physical address? If the former, it's
prototype is wrong, and its 4th argument needs to be typed as
'void __iomem *' rather than 'unsigned long'. If the latter, the code
above is wrong.
Do you see what I'm getting at now?
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