On Tue, Sep 23, 2025 at 1:46 AM Jjian Zhou (周建) [off-list ref] wrote:

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

quoted

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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

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[1];
+};

Can we ignore this error?

It seems single element style is deprecated. While we know what we are
doing, let us placate that error by
       struct mbox_chan mch;
       struct mbox_chan chans[];
and set  chans = &mch