linux-kernel - Re: [PATCH v8 1/2] irqchip: imx-gpcv2: IMX GPCv2 driver for wakeup sources

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Message-ID: <alpine.DEB.2.11.1508231251040.3873@nanos>
Date:	Sun, 23 Aug 2015 12:57:52 +0200 (CEST)
From:	Thomas Gleixner <tglx@...utronix.de>
To:	Shenwei Wang <shenwei.wang@...escale.com>
cc:	shawn.guo@...aro.org, jason@...edaemon.net,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	b20788@...escale.com
Subject: Re: [PATCH v8 1/2] irqchip: imx-gpcv2: IMX GPCv2 driver for wakeup
 sources

On Fri, 31 Jul 2015, Shenwei Wang wrote:
> +struct gpcv2_irqchip_data {
> +	struct raw_spinlock rlock;
> +	void __iomem *gpc_base;
> +	u32 wakeup_sources[IMR_NUM];
> +	u32 enabled_irqs[IMR_NUM];
> +	u32 cpu2wakeup;

Can you please format that in a readable way?

      struct raw_spinlock    rlock;
      void __iomem	     *gpc_base;
      ....

> +};
> +
> +static struct gpcv2_irqchip_data *imx_gpcv2_instance;
> +
> +u32 imx_gpcv2_get_wakeup_source(u32 **sources)
> +{
> +	if (!imx_gpcv2_instance)
> +		return 0;
> +
> +	if (sources)
> +		*sources = imx_gpcv2_instance->wakeup_sources;
> +
> +	return IMR_NUM;
> +}
> +
> +static int gpcv2_wakeup_source_save(void)
> +{
> +	struct gpcv2_irqchip_data *cd;
> +	void __iomem *reg;
> +	int i;
> +
> +	cd = imx_gpcv2_instance;
> +	if (!cd)
> +		return 0;
> +
> +	for (i = 0; i < IMR_NUM; i++) {
> +		reg = cd->gpc_base + cd->cpu2wakeup + i * 4;
> +		cd->enabled_irqs[i] = readl_relaxed(reg);

You read the full state of the register and restore the full state. So
why enabled_irqs?

> +		writel_relaxed(cd->wakeup_sources[i], reg);
> +	}
> +
> +	return 0;
> +}
> +
> +static void gpcv2_wakeup_source_restore(void)
> +{
> +	struct gpcv2_irqchip_data *cd;
> +	void __iomem *reg;
> +	int i;
> +
> +	cd = imx_gpcv2_instance;
> +	if (!cd)
> +		return;
> +
> +	for (i = 0; i < IMR_NUM; i++) {
> +		reg = cd->gpc_base + cd->cpu2wakeup + i * 4;
> +		writel_relaxed(cd->enabled_irqs[i], reg);
> +		cd->wakeup_sources[i] = ~0;

Why are you clearing that info on resume? Drivers will clear that via
set_wake() or leave it when they want to have resume functionality?

> +static int __init imx_gpcv2_irqchip_init(struct device_node *node,
> +			       struct device_node *parent)
> +{
> +	struct irq_domain *parent_domain, *domain;
> +	struct gpcv2_irqchip_data *cd;
> +	int i;
> +
> +	if (!parent) {
> +		pr_err("%s: no parent, giving up\n", node->full_name);
> +		return -ENODEV;
> +	}
> +
> +	parent_domain = irq_find_host(parent);
> +	if (!parent_domain) {
> +		pr_err("%s: unable to get parent domain\n", node->full_name);
> +		return -ENXIO;
> +	}
> +
> +	cd = kzalloc(sizeof(struct gpcv2_irqchip_data), GFP_KERNEL);
> +	BUG_ON(!cd);

You return an error code for all other failures. Why BUG here?

Otherwise this looks very clean now. Can you please resend ASAP with
these minor points addressed?

Thanks,

	tglx


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