Re: [PATCH 1/2] bus: omap_l3_noc: Add resume hook to restore context

[Nishanth Menon <nm@ti.com>]

On 11/09/2014 11:03 PM, Keerthy wrote:
> On certain SoCs such as AM437x SoC, L3_noc error registers are
> maintained in power domain such as per domain which looses context as part
> of low power state such as RTC+DDR mode. On these platforms when we
> mask interrupts which we cannot handle, the source of these interrupts
> still remain on resume, however, the flag mux registers now contain
> their reset value (unmasked) - this breaks the system with infinite
> interrupts since we do not these interrupts to take place ever again.
> 
> To handle this: restore the masking of interrupts which we have
> already recorded in the system as ones we cannot handle.
> 
> Fixes: 654fa7979b5db9a44b8 ("bus: omap_l3_noc: ignore masked out unclearable targets")
please use instead:
Fixes: 2100b595b7 ("bus: omap_l3_noc: ignore masked out unclearable
targets")

?


> Signed-off-by: Keerthy <j-keerthy@ti.com>
> ---
>  drivers/bus/omap_l3_noc.c |   55 +++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 55 insertions(+)
> 
> diff --git a/drivers/bus/omap_l3_noc.c b/drivers/bus/omap_l3_noc.c
> index 531ae59..b5eac29 100644
> --- a/drivers/bus/omap_l3_noc.c
> +++ b/drivers/bus/omap_l3_noc.c
> @@ -296,11 +296,66 @@ static int omap_l3_probe(struct platform_device *pdev)
>  	return ret;
>  }
>  
> +#ifdef	CONFIG_PM
> +
> +/**
> + * l3_resume_noirq() - resume function for l3_noc
> + * @dev:	pointer to l3_noc device structure
> + *
> + * We only have the resume handler only since we
> + * have already maintained the delta register
> + * configuration as part of configuring the system
> + */
> +static int l3_resume_noirq(struct device *dev)
> +{
> +	struct omap_l3 *l3 = dev_get_drvdata(dev);
> +	int i;
> +	struct l3_flagmux_data *flag_mux;
> +	void __iomem *base, *mask_regx = NULL;
> +	u32 mask_val;
> +
> +	for (i = 0; i < l3->num_modules; i++) {
> +		base = l3->l3_base[i];
> +		flag_mux = l3->l3_flagmux[i];
> +		if (!flag_mux->mask_app_bits && !flag_mux->mask_dbg_bits)
> +			continue;
> +
> +		mask_regx = base + flag_mux->offset + L3_FLAGMUX_MASK0 +
> +			   (L3_APPLICATION_ERROR << 3);
> +		mask_val = readl_relaxed(mask_regx);
> +		mask_val &= ~(flag_mux->mask_app_bits);
> +
> +		writel_relaxed(mask_val, mask_regx);
> +		mask_regx = base + flag_mux->offset + L3_FLAGMUX_MASK0 +
> +			   (L3_DEBUG_ERROR << 3);
> +		mask_val = readl_relaxed(mask_regx);
> +		mask_val &= ~(flag_mux->mask_dbg_bits);
> +
> +		writel_relaxed(mask_val, mask_regx);
> +	}
> +
> +	/* Dummy read to force OCP barrier */
> +	if (mask_regx)
> +		(void)readl(mask_regx);
> +
> +	return 0;
> +}
> +
> +static const struct dev_pm_ops l3_dev_pm_ops = {
> +	.resume_noirq		= l3_resume_noirq,
> +};
> +
> +#define L3_DEV_PM_OPS (&l3_dev_pm_ops)
> +#else
> +#define L3_DEV_PM_OPS NULL
> +#endif
> +
>  static struct platform_driver omap_l3_driver = {
>  	.probe		= omap_l3_probe,
>  	.driver		= {
>  		.name		= "omap_l3_noc",
>  		.owner		= THIS_MODULE,
> +		.pm		= L3_DEV_PM_OPS,
>  		.of_match_table = of_match_ptr(l3_noc_match),
>  	},
>  };
> 


-- 
Regards,
Nishanth Menon