On Thu, Jan 24, 2019 at 11:59:43AM +0000, Andre Przywara wrote:
> On Thu, 24 Jan 2019 11:16:29 +0000
> Alexandru Elisei <alexandru.elisei@xxxxxxx> wrote:
>
> > A warning is displayed if uart0_base is different from what the code
> > expects qemu to generate for the pl011 UART in the device tree.
> > However, now we support the ns16550a UART emulated by kvmtool, which
> > has a different address. This leads to the warning being displayed
> > even though the UART is configured and working as expected.
> >
> > Now that we support multiple UARTs, the warning serves no purpose, so
> > remove it.
>
> Mmh, but we use that address before, right? So for anything not
> emulating an UART at this QEMU specific address we write to some random
> (device) memory?
>
> Drew, how important is this early print feature for kvm-unit-tests?
The setup code passes through quite a few asserts before getting through
io_init() (including in uart0_init), so I think there's still value in
having a guessed UART address. Maybe we can provide guesses for both
QEMU and kvmtool, and some selection method, that would be used until
we've properly assigned uart0_base from DT?
>
> Cheers,
> Andre.
>
> >
> > Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
> > ---
> > lib/arm/io.c | 6 ------
> > 1 file changed, 6 deletions(-)
> >
> > diff --git a/lib/arm/io.c b/lib/arm/io.c
> > index 35fc05aeb4db..87435150f73e 100644
> > --- a/lib/arm/io.c
> > +++ b/lib/arm/io.c
> > @@ -61,12 +61,6 @@ static void uart0_init(void)
> > }
> >
> > uart0_base = ioremap(base.addr, base.size);
> > -
> > - if (uart0_base != (u8 *)UART_EARLY_BASE) {
> > - printf("WARNING: early print support may not work. "
> > - "Found uart at %p, but early base is %p.\n",
> > - uart0_base, (u8 *)UART_EARLY_BASE);
> > - }
> > }
This warning is doing what it should, which is pointing out that the
UART_EARLY_BASE guess appears to be wrong. If we can provide a way
to support more than one guess, then we should keep this warning but
adjust it to match one of any of the guesses.
Thanks,
drew
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