Re: [PATCH v4 1/3] usb: chipidea: imx: Change switch order

[Fabien Lahoudere]

Hi,

On 21/09/16 08:57, Peter Chen wrote:
> On Mon, Sep 19, 2016 at 01:45:38PM +0200, Fabien Lahoudere wrote:
> > Each USB controller have different behaviour, so in order to avoid to have
> > several "swicth(data->index)" and lock/unlock, we prefer to get the index
> > switch and then test for features if they exist for this index.
> > This patch also remove useless test of reg and val. Those two values cannot
> > be NULL.
>
> Sorry, I can't see the benefits of this change.
> Considering certain controller doesn't have oc feature, with current
> code it only needs one comparison (flag disable_oc), but with your
> changes, it needs two comparisons.

The benefits are visible with next patches only but you ask me to split 
it, so I do.

Thanks

Fabien

> Peter
> > Signed-off-by: Fabien Lahoudere <fabien.lahoudere@xxxxxxxxxxxxxxx>
> > ---
> >  drivers/usb/chipidea/usbmisc_imx.c | 38 ++++++++++++++++++++++++--------------
> >  1 file changed, 24 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/usb/chipidea/usbmisc_imx.c b/drivers/usb/chipidea/usbmisc_imx.c
> > index 20d02a5..9549821 100644
> > --- a/drivers/usb/chipidea/usbmisc_imx.c
> > +++ b/drivers/usb/chipidea/usbmisc_imx.c
> > @@ -199,31 +199,41 @@ static int usbmisc_imx53_init(struct imx_usbmisc_data *data)
> >  	val |= MX53_USB_PLL_DIV_24_MHZ;
> >  	writel(val, usbmisc->base + MX53_USB_OTG_PHY_CTRL_1_OFFSET);
> >
> > -	if (data->disable_oc) {
> > -		spin_lock_irqsave(&usbmisc->lock, flags);
> > -		switch (data->index) {
> > -		case 0:
> > +	spin_lock_irqsave(&usbmisc->lock, flags);
> > +
> > +	switch (data->index) {
> > +	case 0:
> > +		if (data->disable_oc) {
> >  			reg = usbmisc->base + MX53_USB_OTG_PHY_CTRL_0_OFFSET;
> >  			val = readl(reg) | MX53_BM_OVER_CUR_DIS_OTG;
> > -			break;
> > -		case 1:
> > +			writel(val, reg);
> > +		}
> > +		break;
> > +	case 1:
> > +		if (data->disable_oc) {
> >  			reg = usbmisc->base + MX53_USB_OTG_PHY_CTRL_0_OFFSET;
> >  			val = readl(reg) | MX53_BM_OVER_CUR_DIS_H1;
> > -			break;
> > -		case 2:
> > +			writel(val, reg);
> > +		}
> > +		break;
> > +	case 2:
> > +		if (data->disable_oc) {
> >  			reg = usbmisc->base + MX53_USB_UH2_CTRL_OFFSET;
> >  			val = readl(reg) | MX53_BM_OVER_CUR_DIS_UHx;
> > -			break;
> > -		case 3:
> > +			writel(val, reg);
> > +		}
> > +		break;
> > +	case 3:
> > +		if (data->disable_oc) {
> >  			reg = usbmisc->base + MX53_USB_UH3_CTRL_OFFSET;
> >  			val = readl(reg) | MX53_BM_OVER_CUR_DIS_UHx;
> > -			break;
> > -		}
> > -		if (reg && val)
> >  			writel(val, reg);
> > -		spin_unlock_irqrestore(&usbmisc->lock, flags);
> > +		}
> > +		break;
> >  	}
> >
> > +	spin_unlock_irqrestore(&usbmisc->lock, flags);
> > +
> >  	return 0;
> >  }
> >
> > --
> > 2.1.4