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

From: Sudeep Holla
Date: Mon Sep 22 2014 - 14:16:10 EST




On 22/09/14 19:01, Ashwin Chaugule wrote:
Hi Jassi,

On 1 August 2014 08:31, Jassi Brar <jaswinder.singh@xxxxxxxxxx> 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@xxxxxxxxxx>
---
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

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