Re: [PATCH] mailbox: add tx_prepare client callback

From: Jassi Brar
Date: Tue Nov 11 2014 - 12:53:50 EST


On 11 November 2014 21:34, Sudeep Holla <sudeep.holla@xxxxxxx> wrote:
> If the mailbox controller expects the payload is in place before
> initiating the transmit, then it's impossible to reuse the list
> maintained by core mailbox code currently. Maintaining another list
> for sending the message in the controller seems totally unnecessary
> as core mailbox library already provides that feature.
>
> This patch introduces tx_prepare callback in mbox_client which
> can be used by the core mailbox library before initiating the
> transaction through mbox->ops->send_data. The client driver can
> implement this callback to ensure the payload is copied to the
> shared memory.
>
> Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
> Cc: Jassi Brar <jaswinder.singh@xxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> drivers/mailbox/mailbox.c | 2 ++
> include/linux/mailbox_client.h | 1 +
> 2 files changed, 3 insertions(+)
>
> diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
> index afcb430508ec..4b4044f47b45 100644
> --- a/drivers/mailbox/mailbox.c
> +++ b/drivers/mailbox/mailbox.c
> @@ -76,6 +76,8 @@ static void msg_submit(struct mbox_chan *chan)
>
> data = chan->msg_data[idx];
>
> + if (chan->cl->tx_prepare)
> + chan->cl->tx_prepare(chan->cl, data);
> /* Try to submit a message to the MBOX controller */
> err = chan->mbox->ops->send_data(chan, data);
> if (!err) {
> diff --git a/include/linux/mailbox_client.h b/include/linux/mailbox_client.h
> index 307d9cab2026..5a1a6db63e96 100644
> --- a/include/linux/mailbox_client.h
> +++ b/include/linux/mailbox_client.h
> @@ -34,6 +34,7 @@ struct mbox_client {
> bool knows_txdone;
>
> void (*rx_callback)(struct mbox_client *cl, void *mssg);
> + void (*tx_prepare)(struct mbox_client *cl, void *mssg);
> void (*tx_done)(struct mbox_client *cl, void *mssg, int r);
> };
>
Please add some documentation for tx_prepare() as well.

Thanks
Jassi
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