Re: [Qemu-devel] [Qemu-ppc] [PATCH v6 4/5] ppc440_uc: Basic emulation of PPC440 DMA controller

From: David Gibson <david@gibson.dropbear.id.au>
To: BALATON Zoltan <balaton@eik.bme.hu>
Cc: Cedric Le Goater <clg@kaod.org>,
	qemu-ppc@nongnu.org, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [Qemu-ppc] [PATCH v6 4/5] ppc440_uc: Basic emulation of PPC440 DMA controller
Date: Mon, 2 Jul 2018 10:03:31 +1000	[thread overview]
Message-ID: <20180702000331.GQ3422@umbus.fritz.box> (raw)
In-Reply-To: <alpine.BSF.2.21.1806291410520.18342@zero.eik.bme.hu>

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On Fri, Jun 29, 2018 at 02:14:49PM +0200, BALATON Zoltan wrote:
> On Fri, 29 Jun 2018, David Gibson wrote:
> > On Fri, Jun 29, 2018 at 02:48:40PM +1000, David Gibson wrote:
> > > On Fri, Jun 29, 2018 at 12:38:33AM +0200, BALATON Zoltan wrote:
> > > > PPC440 SoCs such as the AMCC 460EX have a DMA controller which is used
> > > > by AmigaOS on the sam460ex. Implement the parts used by AmigaOS so it
> > > > can get further booting on the sam460ex machine.
> > > > 
> > > > Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
> > > > ---
> > > > v6:
> > > > - CamelCase type names
> > > > - Check return value of cpu_physical_memory_map
> > > 
> > > I don't really have the knowledge to review this, but since it's a new
> > > device that no-one else is using, I've applied it.
> > 
> > I take that back.  This breaks compile for me with:
> > 
> >  CC      ppc-softmmu/hw/ppc/ppc440_uc.o
> > /home/dwg/src/qemu/hw/ppc/ppc440_uc.c: In function ‘dcr_write_dma’:
> > /home/dwg/src/qemu/hw/ppc/ppc440_uc.c:907:35: error: ‘sidx’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
> >                     int width, i, sidx, didx;
> >                                   ^~~~
> > /home/dwg/src/qemu/hw/ppc/ppc440_uc.c:935:25: error: ‘didx’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
> >                         cpu_physical_memory_unmap(wptr, wlen, 1, didx);
> >                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > 
> > gcc 8.1.1 on Fedora 28.
> 
> Sorry, this was introduced in v6 when trying to handle return values from
> cpu_physical_memory_map. I've sent a v7 of just this patch that should fix
> this.
> 
> There was also a 5/5 in this series which is useful even by itself without
> the OpenBIOS patch as it allows MorphOS to get further on sam460ex even if
> it's not booting yet. Just let you know, that it's not tied to the OpenBIOS
> change in case this wasn't clear from the commit message.

Right.  I haven't forgotten it, I just hadn't yet found time to
research the change a bit more thorougly.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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