Re: [PATCH 1/2] hw/display/xlnx_dp.c: Don't abort on AUX FIFO overrun/underrun

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 6/11/25 15:52, Peter Maydell wrote:
> The documentation of the Xilinx DisplayPort subsystem at
> https://www.xilinx.com/support/documents/ip_documentation/v_dp_txss1/v3_1/pg299-v-dp-txss1.pdf
> doesn't say what happens if a guest tries to issue an AUX write
> command with a length greater than the amount of data in the AUX
> write FIFO, or tries to write more data to the write FIFO than it can
> hold, or issues multiple commands that put data into the AUX read
> FIFO without reading it such that it overflows.
> 
> Currently QEMU will abort() in these guest-error situations, either
> in xlnx_dp.c itself or in the fifo8 code.  Make these cases all be
> logged as guest errors instead.  We choose to ignore the new data on
> overflow, and return 0 on underflow. This is in line with how we handled
> the "read from empty RX FIFO" case in commit a09ef5040477.
> 
> Cc: qemu-stable@nongnu.org
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1418
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1419
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1424
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>   hw/display/xlnx_dp.c | 28 ++++++++++++++++++++++++++--
>   1 file changed, 26 insertions(+), 2 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>