NOC (interconnect) lockup on i.MX8MP during resume

[Ahmad Fatoum]

Hello Alexander,

On 09.03.23 15:57, Alexander Stein 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?

Could it be that you don't have a fully featured 8MP, but a 8MPUL
or 8MPL, which lacks VPUs? In that case, it's not enough to disable
the VPU nodes in the DT, but you need to disable the VPU power domains as well.

Cheers,
Ahmad

> 
> 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<---
> 

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |