Re: IOMMU problem on Xen dom0 arm (Was: Re: Xen on arm Chromebook seems to cause no display on screen)

[Julien Grall <julien@xxxxxxx>]

Hi Chuck,

On 27/10/2023 04:42, Chuck Zmudzinski wrote:
> On 10/26/2023 5:24 PM, Julien Grall wrote:
> > I am not quite too sure why the check implies the IOMMU is not
> > supported. That said, I vaguely recall that Linux will update the DMA
> > ops when running under Xen. Would you be able to print the two values
> > returned ("%pS" should give the symbol)?
> I got those values:
>
> [    2.552094] [drm] dma_ops(priv->dma_dev): 0xc0d018c0, dma_ops(subdrv_dev): 
> 0xc0d662dc
>
> I presume you know how to interpret those. The failed test is that they are not 
> equal.
Unfortunately the values are specific to the kernel build.

From [1], I was expecting that %pS would print something like:

        %pS     versatile_init+0x0/0x110

Can you use 'nm', gdb or addr2line to find out the associated the symbols?

Cheers,

[1] https://www.kernel.org/doc/Documentation/printk-formats.txt

--
Julien Grall