Re: [PATCHv10 2/4] mailbox: Introduce framework for mailbox

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

On 22/09/14 19:01, Ashwin Chaugule wrote:
> Hi Jassi,
>
> On 1 August 2014 08:31, Jassi Brar <jaswinder.singh@linaro.org> wrote:
>> Introduce common framework for client/protocol drivers and
>> controller drivers of Inter-Processor-Communication (IPC).
>>
>> Client driver developers should have a look at
>>   include/linux/mailbox_client.h to understand the part of
>> the API exposed to client drivers.
>> Similarly controller driver developers should have a look
>> at include/linux/mailbox_controller.h
>>
>> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
>> ---
>>   MAINTAINERS                        |   8 +
>>   drivers/mailbox/Makefile           |   4 +
>>   drivers/mailbox/mailbox.c          | 466 +++++++++++++++++++++++++++++++++++++
>>   include/linux/mailbox_client.h     |  46 ++++
>>   include/linux/mailbox_controller.h | 135 +++++++++++
>>   5 files changed, 659 insertions(+)
>>   create mode 100644 drivers/mailbox/mailbox.c
>>   create mode 100644 include/linux/mailbox_client.h
>>   create mode 100644 include/linux/mailbox_controller.h
>>
>
> [..]
>
>> +
>> +static void poll_txdone(unsigned long data)
>> +{
>> +       struct mbox_controller *mbox = (struct mbox_controller *)data;
>> +       bool txdone, resched = false;
>> +       int i;
>> +
>> +       for (i = 0; i < mbox->num_chans; i++) {
>> +               struct mbox_chan *chan = &mbox->chans[i];
>> +
>> +               if (chan->active_req && chan->cl) {
>> +                       resched = true;
>> +                       txdone = chan->mbox->ops->last_tx_done(chan);
>> +                       if (txdone)
>> +                               tx_tick(chan, 0);
>> +               }
>> +       }
>> +
>> +       if (resched)
>> +               mod_timer(&mbox->poll, jiffies +
>> +                               msecs_to_jiffies(mbox->period));
>
> While preparing a different patch which uses the Mbox framework, I
> noticed that mbox->period might not be initialized anywhere. Also, how
> is mbox->txpoll_period to be used? It appears from the description of
> txpoll_period in mbox_controller.h that you'd want to use that value
> in the mod_timer above, or equate the two somewhere in the controller
> registration or eliminate one of the two. FWIW I also looked at your
> code in [1].
>

IIUC the controller needs to set the txpoll_period if it sets
txdone_poll, may be a sanity check for !0 would be good.

Regards,
Sudeep