Re: [Qemu-devel] [PATCH] aspeed/smc: snoop SPI transfers to fake dummy cycles

[Cédric Le Goater]

On 1/24/19 2:24 PM, Peter Maydell wrote:
> On Mon, 21 Jan 2019 at 15:49, Cédric Le Goater <address@hidden> wrote:
>>
>> The m25p80 models dummy cycles using byte transfers. This works well
>> when the transfers are initiated by the QEMU model of a SPI controller
>> but when these are initiated by the OS, it breaks emulation.
>>
>> Snoop the SPI transfer to catch commands requiring dummy cycles and
>> replace them with byte transfers compatible with the m25p80 model.
>>
>> Signed-off-by: Cédric Le Goater <address@hidden>
>> ---
> 
> This fails to compile:
> 
> /home/petmay01/linaro/qemu-from-laptop/qemu/hw/ssi/aspeed_smc.c: In
> function ‘aspeed_smc_do_snoop’:
> /home/petmay01/linaro/qemu-from-laptop/qemu/hw/ssi/aspeed_smc.c:646:42:
> error: ‘R_DUMMY_DATA’ undeclared (first use in this function)
>              ssi_transfer(s->spi, s->regs[R_DUMMY_DATA] & 0xff);
>                                           ^
> /home/petmay01/linaro/qemu-from-laptop/qemu/hw/ssi/aspeed_smc.c:646:42:
> note: each undeclared identifier is reported only once for each
> function it appears in
> /home/petmay01/linaro/qemu-from-laptop/qemu/rules.mak:69: recipe for
> target 'hw/ssi/aspeed_smc.o' failed
> 
> Is it dependent on some other patch ?

oups. sorry :/ it depends on another patch adding this register. 

I will build a patchset for the whole. It shouldn't be controversial.
I haven't add time to rework the DMA support so I will leave that out.

Thanks,

C.