From: YannickV <Y.Vossen@beckhoff.com>

During the emulation startup, all registers are reset, which triggers the
`r_unlock_post_write` function with a value of 0. This led to an
unintended memory access disable, making the devcfg unusable.

During startup, the memory space no longer gets locked.

Signed-off-by: Yannick Voßen <y.vossen@beckhoff.com>
---
 hw/dma/xlnx-zynq-devcfg.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/hw/dma/xlnx-zynq-devcfg.c b/hw/dma/xlnx-zynq-devcfg.c
index b838c1c0d0..f28d0015e6 100644
--- a/hw/dma/xlnx-zynq-devcfg.c
+++ b/hw/dma/xlnx-zynq-devcfg.c
@@ -221,7 +221,9 @@ static void r_unlock_post_write(RegisterInfo *reg, uint64_t val)
 {
     XlnxZynqDevcfg *s = XLNX_ZYNQ_DEVCFG(reg->opaque);
     const char *device_prefix = object_get_typename(OBJECT(s));
-
+    if (device_is_in_reset(DEVICE(s))) {
+        return;
+    }
     if (val == R_UNLOCK_MAGIC) {
         DB_PRINT("successful unlock\n");
         s->regs[R_CTRL] |= R_CTRL_PCAP_PR_MASK;
-- 
2.50.1

On Fri, Aug 15, 2025 at 11:01:02AM +0200, Corvin Köhne wrote:
> From: YannickV <Y.Vossen@beckhoff.com>
> 
> During the emulation startup, all registers are reset, which triggers the
> `r_unlock_post_write` function with a value of 0. This led to an
> unintended memory access disable, making the devcfg unusable.
> 
> During startup, the memory space no longer gets locked.
> 
> Signed-off-by: Yannick Voßen <y.vossen@beckhoff.com>

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@amd.com>



> ---
>  hw/dma/xlnx-zynq-devcfg.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/dma/xlnx-zynq-devcfg.c b/hw/dma/xlnx-zynq-devcfg.c
> index b838c1c0d0..f28d0015e6 100644
> --- a/hw/dma/xlnx-zynq-devcfg.c
> +++ b/hw/dma/xlnx-zynq-devcfg.c
> @@ -221,7 +221,9 @@ static void r_unlock_post_write(RegisterInfo *reg, uint64_t val)
>  {
>      XlnxZynqDevcfg *s = XLNX_ZYNQ_DEVCFG(reg->opaque);
>      const char *device_prefix = object_get_typename(OBJECT(s));
> -
> +    if (device_is_in_reset(DEVICE(s))) {
> +        return;
> +    }
>      if (val == R_UNLOCK_MAGIC) {
>          DB_PRINT("successful unlock\n");
>          s->regs[R_CTRL] |= R_CTRL_PCAP_PR_MASK;
> -- 
> 2.50.1
>