[PATCH v2, 1/1] mailbox: cmdq: add instruction time-out interrupt support

[yongqiang.niu]

On Tue, 2021-10-05 at 07:41 +0800, Chun-Kuang Hu wrote:
> Hi, Yongqiang:
> 
> Yongqiang Niu <yongqiang.niu at mediatek.com> 於 2021年9月30日 週四 下午9:18寫道：
> > 
> > add time-out cycle setting to make sure time-out interrupt irq
> > will happened when instruction time-out for wait and poll
> > 
> > Signed-off-by: Yongqiang Niu <yongqiang.niu at mediatek.com>
> > ---
> >  drivers/mailbox/mtk-cmdq-mailbox.c | 11 +++++++++++
> >  1 file changed, 11 insertions(+)
> > 
> > diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c
> > b/drivers/mailbox/mtk-cmdq-mailbox.c
> > index 64175a893312..197b03222f94 100644
> > --- a/drivers/mailbox/mtk-cmdq-mailbox.c
> > +++ b/drivers/mailbox/mtk-cmdq-mailbox.c
> > @@ -36,6 +36,7 @@
> >  #define CMDQ_THR_END_ADDR              0x24
> >  #define CMDQ_THR_WAIT_TOKEN            0x30
> >  #define CMDQ_THR_PRIORITY              0x40
> > +#define CMDQ_THR_INSTN_TIMEOUT_CYCLES  0x50
> > 
> >  #define GCE_GCTL_VALUE                 0x48
> > 
> > @@ -54,6 +55,15 @@
> >  #define CMDQ_JUMP_BY_OFFSET            0x10000000
> >  #define CMDQ_JUMP_BY_PA                        0x10000001
> > 
> > +/*
> > + * instruction time-out
> > + * cycles to issue instruction time-out interrupt for wait and
> > poll instructions
> > + * GCE axi_clock 156MHz
> > + * 1 cycle = 6.41ns
> > + * instruction time out 2^22*2*6.41ns = 53ms
> 
> For different clients, the timeout value would be different, and each
> client could use timer to detect timeout, so it's not necessary to
> enable timeout in cmdq driver.
> 
> Regards,
> Chun-Kuang.

if we do not set cmdq hardware timeout, this condition will never
happen
cmdq_thread_irq_handler
if (irq_flag & CMDQ_THR_IRQ_ERROR)
		err = true;

and no error callback 
else if (err) {
			cmdq_task_exec_done(task, -ENOEXEC);
			cmdq_task_handle_error(curr_task);
			kfree(task);
		}
the client will never received the error callback, cmdq hardware will
poll the event for ever and no report timeout 
> 
> > + */
> > +#define CMDQ_INSTN_TIMEOUT_CYCLES      22
> > +
> >  struct cmdq_thread {
> >         struct mbox_chan        *chan;
> >         void __iomem            *base;
> > @@ -376,6 +386,7 @@ static int cmdq_mbox_send_data(struct mbox_chan
> > *chan, void *data)
> >                 writel((task->pa_base + pkt->cmd_buf_size) >> cmdq-
> > >shift_pa,
> >                        thread->base + CMDQ_THR_END_ADDR);
> > 
> > +               writel(CMDQ_INSTN_TIMEOUT_CYCLES, thread->base +
> > CMDQ_THR_INSTN_TIMEOUT_CYCLES);
> >                 writel(thread->priority, thread->base +
> > CMDQ_THR_PRIORITY);
> >                 writel(CMDQ_THR_IRQ_EN, thread->base +
> > CMDQ_THR_IRQ_ENABLE);
> >                 writel(CMDQ_THR_ENABLED, thread->base +
> > CMDQ_THR_ENABLE_TASK);
> > --
> > 2.25.1
> >