Messages in this thread | | | From | Jassi Brar <> | Date | Thu, 6 Apr 2017 22:45:26 +0530 | Subject | Re: [PATCH] mailbox: fix completion order for blocking requests |
| |
On 6 April 2017 at 22:28, Alexey Klimov <alexey.klimov@arm.com> wrote: > Hi Jassi/Sudeep, > > On Wed, Mar 29, 2017 at 07:01:09PM +0100, Sudeep Holla wrote: >> >> >> On 29/03/17 18:43, Jassi Brar wrote: ...
>> > diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c >> > index 9dfbf7e..e06c50c 100644 >> > --- a/drivers/mailbox/mailbox.c >> > +++ b/drivers/mailbox/mailbox.c >> > @@ -41,6 +41,7 @@ static int add_to_rbuf(struct mbox_chan *chan, void *mssg) >> > >> > idx = chan->msg_free; >> > chan->msg_data[idx] = mssg; >> > + init_completion(&chan->tx_cmpl[idx]); >> >> reinit would be better. > Of course.
.... > From: Alexey Klimov <alexey.klimov@arm.com> > Date: Thu, 6 Apr 2017 13:57:02 +0100 > Subject: [RFC][PATCH] mailbox: per-channel arrays with msg data and completion > structures > > When a mailbox client doesn't serialize sending of the message itself, > and asks mailbox framework to block on mbox_send_message(), one > completion structure per channel is not enough. Client can make a few > mbox_send_message() calls at the same time, and there is no guaranteed > order of going to sleep on completion. > > If mailbox controller acks a message transfer, then tx_tick() wakes up > the first thread that waits on completion. > If mailbox controller doesn't ack the transfer and timeout happens, then > tx_tick() calls complete, and the next caller trying to sleep on > completion wakes up immediately. > > This patch fixes this by changing completion structures to be inserted > into an array that contains a) pointer to data provided by client and > b) the completion structure. Thus active_req field tracks the index of > the current running request that was submitted to mailbox controller. > > Signed-off-by: Alexey Klimov <alexey.klimov@arm.com> > --- > drivers/mailbox/mailbox.c | 40 +++++++++++++++++++++++--------------- > drivers/mailbox/pcc.c | 10 +++++++--- > include/linux/mailbox_controller.h | 24 +++++++++++++++++------ ... > 3 files changed, 49 insertions(+), 25 deletions(-) > Versus 4 files changed, 17 insertions(+), 8 deletions(-)
I think we should just keep it simpler if it works just as fine.
Thanks.
| |