Re: [PATCH 1/5] arm64: zynqmp: Add firmware DT node

[Edgar E. Iglesias]

On Sun, Dec 08, 2019 at 11:19:33PM -0800, Guenter Roeck wrote:
> On 12/8/19 10:42 PM, Michal Simek wrote:
> > Hi, +Edgar
> > 
> > 
> > On 08. 12. 19 23:38, Guenter Roeck wrote:
> > > On Fri, Oct 18, 2019 at 06:07:31PM +0200, Michael Tretter wrote:
> > > > From: Rajan Vaja <address@hidden>
> > > > 
> > > > Add firmware DT node in ZynqMP device tree. This node
> > > > uses bindings as per new firmware interface driver.
> > > > 
> > > > Signed-off-by: Rajan Vaja <address@hidden>
> > > > Signed-off-by: Michal Simek <address@hidden>
> > > > Signed-off-by: Michael Tretter <address@hidden>
> > > 
> > > With this patch applied in the mainline kernel, the qemu xlnx-zcu102
> > > emulation crashes (see below). Any idea what it might take to get
> > > qemu back to working ?
> > 
> > Driver talks through ATF to PMU unit(microblaze). I don't think A53+MB
> > concept is working with mainline qemu. But crash is too hard. It should

Yes, QEMU doesn't support the Cortex-A53s along with the PMU MicroBlaze.

My workaround when using upstream QEMU is a modified DT without the PMU firmware
and with fixed-clock nodes.


> > be no response from PMU and then this panic.
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/firmware/xilinx/zynqmp.c?h=v5.5-rc1#n728
> > 
> 
> Isn't that a bit harsh too ? Normally one would print an error message
> and abort driver instantiation.

I agree, it would be nice if ATF & kernel drivers would somehow handle
this more gracefully.

Cheers,
Edgar


> 
> It sounds like you are saying that qemu's xlnx-zcu102 emulation is
> no longer supported and expected to crash the kernel. Is this a
> correct assumption ? If so, I'll drop it from my list of tests.
> 
> Thanks,
> Guenter