Re: [RESEND PATCH] mailbox: Add dummy mailbox API implementation

[Randy Dunlap <rdunlap@infradead.org>]

On 3/19/20 10:49 AM, Daniel Baluta wrote:
> From: Daniel Baluta <daniel.baluta@nxp.com>
> 
> There are users of mailbox API that could be enabled
> via COMPILE_TEST without select CONFIG_MAILBOX.
> 
> In such cases we got compilation errors, like these:
> 
> ld: drivers/firmware/imx/imx-scu.o: in function `imx_scu_probe':
> imx-scu.c:(.text+0x25e): undefined reference to
> `mbox_request_channel_byname'
> ld: drivers/firmware/imx/imx-scu.o: in function `imx_scu_call_rpc':
> imx-scu.c:(.text+0x4b8): undefined reference to `mbox_send_message'
> ld: drivers/firmware/imx/imx-scu-irq.o: in function
> `imx_scu_enable_general_irq_channel':
> imx-scu-irq.c:(.text+0x34d): undefined reference to
> `mbox_request_channel_byname'
> 
> Fix this by implementing dummy mailbox API when CONFIG_MAILBOX is not
> set.
> 
> Reported-by: Randy Dunlap <rdunlap@infradead.org>
> Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>

Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested

Thanks.

> ---
> resend adding Jassi's email
> 
>  include/linux/mailbox_client.h | 34 ++++++++++++++++++++++++++++++++++
>  1 file changed, 34 insertions(+)
> 
> diff --git a/include/linux/mailbox_client.h b/include/linux/mailbox_client.h
> index 65229a45590f..ab5d130f0b5c 100644
> --- a/include/linux/mailbox_client.h
> +++ b/include/linux/mailbox_client.h
> @@ -37,6 +37,7 @@ struct mbox_client {
>  	void (*tx_done)(struct mbox_client *cl, void *mssg, int r);
>  };
>  
> +#ifdef CONFIG_MAILBOX
>  struct mbox_chan *mbox_request_channel_byname(struct mbox_client *cl,
>  					      const char *name);
>  struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index);
> @@ -46,4 +47,37 @@ void mbox_client_txdone(struct mbox_chan *chan, int r); /* atomic */
>  bool mbox_client_peek_data(struct mbox_chan *chan); /* atomic */
>  void mbox_free_channel(struct mbox_chan *chan); /* may sleep */
>  
> +#else
> +static inline
> +struct mbox_chan *mbox_request_channel_byname(struct mbox_client *cl,
> +					      const char *name)
> +{
> +	return ERR_PTR(-ENOTSUPP);
> +}
> +
> +static inline
> +struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index)
> +{
> +	return ERR_PTR(-ENOTSUPP);
> +}
> +
> +static inline int mbox_send_message(struct mbox_chan *chan, void *mssg)
> +{
> +	return -ENOTSUPP;
> +}
> +
> +static inline int mbox_flush(struct mbox_chan *chan, unsigned long timeout)
> +{
> +	return -ENOTSUPP;
> +}
> +
> +static inline void mbox_client_txdone(struct mbox_chan *chan, int r) { }
> +
> +static inline bool mbox_client_peek_data(struct mbox_chan *chan)
> +{
> +	return false;
> +}
> +
> +static inline void mbox_free_channel(struct mbox_chan *chan) { }
> +#endif
>  #endif /* __MAILBOX_CLIENT_H */
> 


-- 
~Randy