NOC (interconnect) lockup on i.MX8MP during resume

[Alexander Stein]

Hi Adam,

Am Montag, 13. März 2023, 20:17:55 CET schrieb Adam Ford:
> On Thu, Mar 9, 2023 at 9:11 AM Alexander Stein
> 
> <alexander.stein at ew.tq-group.com> wrote:
> > Hi,
> > 
> > while debugging another issue regarding suspend/resume I noticed that the
> > imx interconnect driver locks up the system when writing into registers.
> > This happens during resume of the 'g2' power domain.
> > imx8m_blk_ctrl_power_on() will eventually call down to
> > imx_icc_node_set(). Using the debug diff furthe down I get this output:
> > 
> > [   71.493062] imx_icc_node_set: node: VPU G2
> > [   71.497163] imx_icc_node_set: peak_bw: 1
> > [   71.501091] imx_icc_node_set: prio: 0x80000303
> > <freeze here>
> > 
> > Unfortunately there is absolutely no documentation regarding NOC in the
> > reference manual, so no idea whats happening here.
> > This is on next-20230309 using imx8mp-tqma8mpql-mba8mpxl.dts with USB
> > disabled (prevents suspend) and Ethernet-PHY-IRQ disabled (the issue I'm
> > tackling).
> > Is there some idea what do in order to support resume on i.MX8MP?
> 
> I haven't played with suspend-resume myself, but there was a thread
> [1] with discussions about fixing a race condition on the imx8mp
> interconnect.

Thanks for this link, but I think this is addressing a race condition during 
(un)registering. This works for me so far. I'm dealing with a freezing 
hardware write upon resume.

Best regards,
Alexander


> adam
> 
> [1] -
> https://lore.kernel.org/lkml/20230201101559.15529-5-johan+linaro@kernel.org
> /
> > Best regards,
> > Alexander
> > 
> > ---8<---
> > diff --git a/drivers/interconnect/imx/imx.c
> > b/drivers/interconnect/imx/imx.c index 979ed610f704..93ec79cc7c06 100644
> > --- a/drivers/interconnect/imx/imx.c
> > +++ b/drivers/interconnect/imx/imx.c
> > @@ -44,13 +44,18 @@ static int imx_icc_node_set(struct icc_node *node)
> > 
> >         u32 prio;
> >         u64 freq;
> > 
> > +       pr_info("%s: node: %s\n", __func__, node->name);
> > +       pr_info("%s: peak_bw: %u\n", __func__, node->peak_bw);
> > 
> >         if (node_data->setting && node->peak_bw) {
> >         
> >                 base = node_data->setting->reg +
> >                 node_data->imx_provider->noc_base;
> >                 if (node_data->setting->mode == IMX_NOC_MODE_FIXED) {
> >                 
> >                         prio = node_data->setting->prio_level;
> >                         prio = PRIORITY_COMP_MARK | (prio << 8) | prio;
> > 
> > +                       pr_info("%s: prio: %#x\n", __func__, prio);
> > 
> >                         writel(prio, base + IMX_NOC_PRIO_REG);
> > 
> > +                       pr_info("%s: mode: %#x\n", __func__,
> > node_data->setting->mode);> 
> >                         writel(node_data->setting->mode, base +
> >                         IMX_NOC_MODE_REG);
> > 
> > +                       pr_info("%s: ext_control: #%x\n", __func__,
> > node_data->setting->ext_control);> 
> >                         writel(node_data->setting->ext_control, base +
> >                         IMX_NOC_EXT_CTL_REG);
> >                         dev_dbg(dev, "%s: mode: 0x%x, prio: 0x%x,
> >                         ext_control: 0x%x\n",
> >                         
> >                                 node_data->desc->name,
> >                                 node_data->setting->mode, prio,
> > 
> > ---8<---
> > 
> > --
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> > Amtsgericht München, HRB 105018
> > Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider
> > http://www.tq-group.com/


-- 
TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany
Amtsgericht München, HRB 105018
Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider
http://www.tq-group.com/