Re: [PATCH 1/1] xlnx-versal-ospi: disable reentrancy detection for iomem_dac

[Peter Maydell]

On Tue, 5 Dec 2023 at 10:08, Sai Pavan Boddu <sai.pavan.boddu@amd.com> wrote:
>
> The OSPI DMA reads flash data through the OSPI linear address space (the
> iomem_dac region), because of this the reentrancy guard introduced in
> commit a2e1753b ("memory: prevent dma-reentracy issues") is disabled for
> the memory region.
>
> Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@amd.com>
> ---
>  hw/ssi/xlnx-versal-ospi.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/hw/ssi/xlnx-versal-ospi.c b/hw/ssi/xlnx-versal-ospi.c
> index 1a61679c2f..5123e7dde7 100644
> --- a/hw/ssi/xlnx-versal-ospi.c
> +++ b/hw/ssi/xlnx-versal-ospi.c
> @@ -1772,6 +1772,7 @@ static void xlnx_versal_ospi_init(Object *obj)
>      memory_region_init_io(&s->iomem_dac, obj, &ospi_dac_ops, s,
>                            TYPE_XILINX_VERSAL_OSPI "-dac", 0x20000000);
>      sysbus_init_mmio(sbd, &s->iomem_dac);
> +    s->iomem_dac.disable_reentrancy_guard = true;

Where we set this flag we should have a comment explaining why
we need to do it, please.

PS: for a single patch you don't need to use a separate cover letter;
cover letters are only needed for multi-patch series.

thanks
-- PMM