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

[yongqiang.niu]

On Fri, 2021-10-08 at 22:55 +0800, Chun-Kuang Hu wrote:
> Hi, Yongqiang:
> 
> yongqiang.niu <yongqiang.niu at mediatek.com> 於 2021年10月8日 週五 上午9:49寫道：
> > 
> > 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
> 
> I think there are two way to implement the timeout mechanism. The
> first way is to use the GCE hardware to detect timeout. The second
> way
> is that client driver use timer to detect timeout, when it's timeout,
> use mbox_flush() to clean up the packets in mtk cmdq driver, and
> remove the error handle in irq handler.
> If you think the first way is better, I think you should pass the
> timeout value from client driver to cmdq driver because each client
> driver has different timeout value. And the GCE clock may be
> different
> in each SoC, so use clk_get_rate() to get the clock frequency for
> different SoC.
> 
> Regards,
> Chun-Kuang.

this patch only used for mdp instruction error and and trigger hw
timeout flow, it is for debug, i will abandon this patch and will not
send upstream anymore.

> 
> > > 
> > > > + */
> > > > +#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
> > > >