Re: [PATCH 2/9] mtd: pxa3xx_nand: add a non mandatory ECC clock

Antoine Tenart
2015-01-28T21:13:11Z

Hi Jisheng!

On Wed, Jan 28, 2015 at 11:35:52AM +0800, Jisheng Zhang wrote:
> On Tue, 27 Jan 2015 06:10:09 -0800
> Antoine Tenart <antoine.tenart@free-electrons.com> wrote:
>
> > diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
> > index d00ac392d1c4..2681ec4abafa 100644
> > --- a/drivers/mtd/nand/pxa3xx_nand.c
> > +++ b/drivers/mtd/nand/pxa3xx_nand.c
> > @@ -180,7 +180,7 @@ struct pxa3xx_nand_info {
> > struct nand_hw_control controller;
> > struct platform_device *pdev;
> >
> > - struct clk *clk;
> > + struct clk *clk, *ecc_clk;
> > void __iomem *mmio_base;
> > unsigned long mmio_phys;
> > struct completion cmd_complete, dev_ready;
> > @@ -1608,7 +1608,7 @@ static int alloc_nand_resource(struct platform_device
> > *pdev)
> > spin_lock_init(&chip->controller->lock);
> > init_waitqueue_head(&chip->controller->wq);
> > - info->clk = devm_clk_get(&pdev->dev, NULL);
> > + info->clk = devm_clk_get(&pdev->dev, "nfc");
> > if (IS_ERR(info->clk)) {
>
> Do we need to fall back to unnamed clock here? Otherwise I guess it will break
> other platforms.

Yes, as Andrew pointed out we need to keep the NULL here to avoid
breaking other platforms.

> >
> > /* initialize all interrupts to be disabled */
> > @@ -1687,6 +1694,9 @@ static int alloc_nand_resource(struct platform_device
> > *pdev) fail_free_buf:
> > free_irq(irq, info);
> > kfree(info->data_buff);
> > +fail_disable_ecc_clk:
> > + if (!IS_ERR(info->ecc_clk))
> > + clk_disable_unprepare(info->ecc_clk);
>
> we can remove the IS_ERR check to simplify this error path since commit
> 63589e92c2d9("clk: Ignore error and NULL pointers passed to clk_{unprepare, disable}()")
>
> > fail_disable_clk:
> > clk_disable_unprepare(info->clk);
> > return ret;
> > @@ -1709,6 +1719,8 @@ static int pxa3xx_nand_remove(struct platform_device
> > *pdev) pxa3xx_nand_free_buff(info);
> >
> > clk_disable_unprepare(info->clk);
> > + if (!IS_ERR(info->ecc_clk))
> > + clk_disable_unprepare(info->ecc_clk);
>
> we can remove the IS_ERR check too.

Yes! Thanks for the hint, I'll remove these useless checks in v2.

Thanks!

Antoine

--
Antoine Ténart, Free Electrons
Embedded Linux, Kernel and Android engineering