Re: [PATCH v1 1/2] staging: Introduce NVIDIA Tegra20 video decoder driver

From: Dan Carpenter
Date: Thu Sep 28 2017 - 03:23:33 EST


On Thu, Sep 28, 2017 at 02:28:04AM +0300, Dmitry Osipenko wrote:
> >> + if (is_baseline_profile)
> >> + frame->aux_paddr = 0xF4DEAD00;
> >
> > The handling of is_baseline_profile is strange to me. It feels like we
> > should always check it before we use ->aux_paddr but we don't ever do
> > that.
> >
>
> In a case of baseline profile, aux buffer isn't needed, HW should't use it. Aux
> phys address is set to a predefined and invalid address, so that in a case of
> VDE trying to use it, its invalid memory accesses would be reported in KMSG by
> memory controller driver and the reported invalid addresses would be known to be
> associated with the aux buffer. I'm not sure what you are meaning.

It's not used perhaps, but we do write it to the hardware, right?

tegra_vde_write_iram_entry(iram_tables, 0, i, value, aux_paddr);

It's just strange.

regards,
dan carpenter