On Tue, Mar 18, 2025 at 02:07:55PM +0100, Corvin Köhne wrote:
> From: YannickV <y.vos...@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.
>
> To address this, a property 'is_initialized' is introduced. It is set
> to false during reset and updated to true once the initialization is
> complete. The unlock function is simply ignored while 'is_initialized'
> is false.
>
> I have no idea how this ever worked. Nevertheless, this restores the
> correct behavior.
>
> Signed-off-by: Yannick Voßen <y.vos...@beckhoff.com>
> ---
> hw/dma/xlnx-zynq-devcfg.c | 6 +++++-
> include/hw/dma/xlnx-zynq-devcfg.h | 2 ++
> 2 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/hw/dma/xlnx-zynq-devcfg.c b/hw/dma/xlnx-zynq-devcfg.c
> index b838c1c0d0..03b5280228 100644
> --- a/hw/dma/xlnx-zynq-devcfg.c
> +++ b/hw/dma/xlnx-zynq-devcfg.c
> @@ -143,9 +143,11 @@ static void xlnx_zynq_devcfg_reset(DeviceState *dev)
> XlnxZynqDevcfg *s = XLNX_ZYNQ_DEVCFG(dev);
> int i;
>
> + s->is_initialized = false;
> for (i = 0; i < XLNX_ZYNQ_DEVCFG_R_MAX; ++i) {
> register_reset(&s->regs_info[i]);
> }
> + s->is_initialized = true;
> }
>
> static void xlnx_zynq_devcfg_dma_go(XlnxZynqDevcfg *s)
> @@ -221,7 +223,9 @@ 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 (!s->is_initialized) {
I think you can use device_is_in_reset(DEVICE(s))
and get rid of is_initialized alltogether?
> + return;
> + }
> if (val == R_UNLOCK_MAGIC) {
> DB_PRINT("successful unlock\n");
> s->regs[R_CTRL] |= R_CTRL_PCAP_PR_MASK;
> diff --git a/include/hw/dma/xlnx-zynq-devcfg.h
> b/include/hw/dma/xlnx-zynq-devcfg.h
> index e4cf085d70..2ab054e598 100644
> --- a/include/hw/dma/xlnx-zynq-devcfg.h
> +++ b/include/hw/dma/xlnx-zynq-devcfg.h
> @@ -55,6 +55,8 @@ struct XlnxZynqDevcfg {
> XlnxZynqDevcfgDMACmd dma_cmd_fifo[XLNX_ZYNQ_DEVCFG_DMA_CMD_FIFO_LEN];
> uint8_t dma_cmd_fifo_num;
>
> + bool is_initialized;
> +
> uint32_t regs[XLNX_ZYNQ_DEVCFG_R_MAX];
> RegisterInfo regs_info[XLNX_ZYNQ_DEVCFG_R_MAX];
> };
> --
> 2.49.0
>
