We log a GUEST_ERROR message "PL011 data written to disabled UART" if
the guest writes data to the TX FIFO when it has not set the enable
bit in the UART. The idea is to note that the guest has done
something dubious but let it work anyway. However, since we print
this message for every output character, it floods the logs when
running a guest that does this.
Keep a note of whether we've printed the log message or not, so we
only output it once. If the guest actively disables the UART, we
re-arm the log message.
Notably, the Linux kernel does not bother to enable the UART if it is
used for earlycon, relying on the firmware having already done that.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Mohamed Mediouni <mohamed@unpredictable.fr>
Message-id: 20260210101702.3980804-1-peter.maydell@linaro.org
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