Re: [PATCH] mailbox: add tx_prepare client callback

[Sudeep Holla <sudeep.holla@arm.com>]

On 11/11/14 17:53, Jassi Brar wrote:
> On 11 November 2014 21:34, Sudeep Holla <sudeep.holla@arm.com> 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@arm.com>
>> Cc: Jassi Brar <jaswinder.singh@linaro.org>
>> Cc: Arnd Bergmann <arnd@arndb.de>
>> ---
>>   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.
>

Ah, sorry for missing that, will add and resend.

Regards,
Sudeep