On 04/07/18 06:33, Sebastian Bauer wrote:
Am 2018-07-04 06:50, schrieb Mark Cave-Ayland:
Either to give up the vga cirrus preference or to apply the same as
was done with the spapr machine. I would prefer the first variant but
it would also cause some differences on other machines.
I understand that the decision was taken to add VGA cirrus to the PPC
build and therefore accept the default VGA device change, however your
the commit message only mentions spapr and not all the other PPC
machines whose defaults are also potentially affected:
$ ./qemu-system-ppc -M ?
Supported machines are:
40p IBM RS/6000 7020 (40p)
bamboo bamboo
g3beige Heathrow based PowerMAC (default)
mac99 Mac99 based PowerMAC
mpc8544ds mpc8544ds
none empty machine
ppce500 generic paravirt e500 platform
prep PowerPC PREP platform
ref405ep ref405ep
sam460ex aCube Sam460ex
taihu taihu
virtex-ml507 Xilinx Virtex ML507 reference design
I'm not able to personally validate all of these, but a quick check
shows that at least both PReP machines (-M prep and -M 40p) are also
broken by this patch which tells me it hasn't had much testing.
David, do you know what the defaults are for the other PPC machines in
order for Sebastian to test and send a follow-up patch?
I don't know much how to validate these machines (I did a 'make check'
but it does not show up any problems) and what impact these change has.
But I suggested in the note section (which is not the commit message)
that some of the machines properly behave different now (OTOH CirrusGD
is a vga card nonetheless, I would have expected that at least the Mac
can deal with that card). This can either be fixed by following the
'spapr' approach (as it explicitly forbids this card as the primary
display and was therefore visible immediately) or by generally
rethinking whether CirrusGD really should be the preferred card over std
vga (after all it is considered as obsolete so why should it be
preferred?). I think it would be nice if a consensus can be found about
the "correct approach" way to fix it. I personally think that adding
more exceptions is not the right way :)
Right, but as the patch submitter it's your responsibility to ensure
that your patch doesn't break other people's machines and/or follow up
with the appropriate patches. If you're not willing to do that then we
should revert the patch in its current form until a better way forward
has been found.
Last but not least, all of the targets should still work as before if
you use -vga std option.
Except that -vga std has been the default for these machines for a long
time, and it's going to be me that will get a large majority of the
complaints if this behaviour changes.
ATB,
Mark.
