On Thu, 2025-09-18 at 18:50 -0500, Jassi Brar wrote:

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On Thu, Aug 21, 2025 at 9:12 PM Jjian Zhou [off-list ref]
wrote:

.....

quoted

+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+struct mtk_vcp_mbox_priv {

Maybe 'mtk_vcp_mbox' is a more appropriate name ?

quoted

+       void __iomem *base;
+       struct device *dev;
+       struct mbox_controller mbox;
+       const struct mtk_vcp_mbox_cfg *cfg;
+       struct mtk_ipi_info ipi_recv;

Maybe also have "struct mbox_chan chan[1]; " so that you don't have
to
allocate one during the probe.
Also if you have  "struct mbox_controller mbox;" as the first member,
you could simply typecast that to get this structure.
Something like "struct mpfs_mbox" in mailbox-mpfs.c

The define "struct mbox_chan chan[1]" has style error.
ERROR:FLEXIBLE_ARRAY: Use C99 flexible arrays - see 
https://docs.kernel.org/process/deprecated.html#zero-length-and-one-element-arrays
#81: FILE: drivers/mailbox/mtk-vcp-mailbox.c:24:
+       struct mbox_chan chans[0];
+};

How about this error?

....

quoted

+
+static struct mbox_chan *mtk_vcp_mbox_xlate(struct mbox_controller
*mbox,
+                                           const struct
of_phandle_args *sp)
+{
+       if (sp->args_count)
+               return NULL;
+
+       return mbox->chans;

return &mbox->chans[0]   seems better.

thnx