On 3 July 2017 at 15:05, Sudeep Holla <sudeep.ho...@arm.com> wrote: > > > On 03/07/17 09:57, Sudeep Holla wrote: >> >> >> On 01/07/17 12:25, Jassi Brar wrote: >>> On Fri, Jun 30, 2017 at 8:44 PM, Sudeep Holla <sudeep.ho...@arm.com> wrote: >>>> Currently the mailbox framework sets txdone_method to TXDONE_BY_POLL if >>>> the controller sets txdone_by_poll. However some clients can have a >>>> mechanism to do TXDONE_BY_ACK which they can specify by knows_txdone. >>>> However, we endup setting both TXDONE_BY_POLL and TXDONE_BY_ACK in that >>>> case. In such scenario, we may end up with below warnings as the tx >>>> ticker is run both by mailbox framework and the client. >>>> >>>> WARNING: CPU: 1 PID: 0 at kernel/time/hrtimer.c:805 >>>> hrtimer_forward+0x88/0xd8 >>>> CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.12.0-rc5 #242 >>>> Hardware name: ARM LTD ARM Juno Development Platform >>>> task: ffff8009768ca700 task.stack: ffff8009768f8000 >>>> PC is at hrtimer_forward+0x88/0xd8 >>>> LR is at txdone_hrtimer+0xd4/0xf8 >>>> Call trace: >>>> hrtimer_forward+0x88/0xd8 >>>> __hrtimer_run_queues+0xe4/0x158 >>>> hrtimer_interrupt+0xa4/0x220 >>>> arch_timer_handler_phys+0x30/0x40 >>>> handle_percpu_devid_irq+0x78/0x130 >>>> generic_handle_irq+0x24/0x38 >>>> __handle_domain_irq+0x5c/0xb8 >>>> gic_handle_irq+0x54/0xa8 >>>> >>>> This patch fixes the issue by resetting TXDONE_BY_POLL if client has set >>>> knows_txdone. >>>> >>>> Cc: Alexey Klimov <alexey.kli...@arm.com> >>>> Cc: Jassi Brar <jaswinder.si...@linaro.org> >>>> Signed-off-by: Sudeep Holla <sudeep.ho...@arm.com> >>>> --- >>>> drivers/mailbox/mailbox.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c >>>> index 537f4f6d009b..8da30f833262 100644 >>>> --- a/drivers/mailbox/mailbox.c >>>> +++ b/drivers/mailbox/mailbox.c >>>> @@ -351,7 +351,7 @@ struct mbox_chan *mbox_request_channel(struct >>>> mbox_client *cl, int index) >>>> init_completion(&chan->tx_complete); >>>> >>>> if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone) >>>> - chan->txdone_method |= TXDONE_BY_ACK; >>>> + chan->txdone_method = TXDONE_BY_ACK; >>>> >>> It has to be restored back in mbox_free_channel() >> >> Ah right, will fix and repost. >> > > I was too fast to response, I see we already take care of that in free > channel. So I think it should be fine as is. > > if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK)) > chan->txdone_method = TXDONE_BY_POLL; > You were too fast this time :)
chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK) is not same as (chan->txdone_method == TXDONE_BY_POLL || chan->txdone_method == TXDONE_BY_ACK)
