[PATCH v4 3/3] xilink-zynq-devcfg: Avoid disabling devcfg memory region during initialization

[Chao Liu]

During the initialization phase, we've encountered an issue where the
UNLOCK register is inadvertently cleared. This results in devcfg MR being
disabled, which in turn leads to unexpected memory access exceptions when
attempting subsequent accesses to the devcfg register. This behavior is not
consistent with the hardware specifications.

This bug was not found earlier because the ignore_memory_transaction_failures
flag was enabled, which ignored exceptions from devcfg devices
when access was disabled.

Signed-off-by: Chao Liu <chao....@yeah.net>
---
 hw/dma/xlnx-zynq-devcfg.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/hw/dma/xlnx-zynq-devcfg.c b/hw/dma/xlnx-zynq-devcfg.c
index e5eff9abc0..af8cc72471 100644
--- a/hw/dma/xlnx-zynq-devcfg.c
+++ b/hw/dma/xlnx-zynq-devcfg.c
@@ -144,7 +144,12 @@ static void xlnx_zynq_devcfg_reset(DeviceState *dev)
     int i;
 
     for (i = 0; i < XLNX_ZYNQ_DEVCFG_R_MAX; ++i) {
-        register_reset(&s->regs_info[i]);
+        if (s->regs_info[i].access) {
+            if (s->regs_info[i].access->addr == A_UNLOCK) {
+                continue;
+            }
+            register_reset(&s->regs_info[i]);
+        }
     }
 }
 
-- 
2.46.1