On Tue, Sep 06, 2016 at 03:53:28PM +0200, Arnd Bergmann wrote:
> Since commit 489447380a29 ("[PATCH] handle errors returned by
> platform_get_irq*()") ten years ago, the locomo driver refuses to
> work without an interrupt line passed in its resources, so the
> check for NO_IRQ is unnecessary.This description is inaccurate and misleading (it looks like it was cut'n'pasted from patch 1.) platform_get_irq() has nothing to do with your change, as your change is more about the irq_base value passed through platform data, and not through IRQ resources. > We still check the irq_base argument for NO_IRQ, but as both > platforms that use locomo (poodle and collie) provide both > 'irq' and 'irq_base', this can be done more consistently > by just checking that both are valid in the probe function > and otherwise returning an error. > > Signed-off-by: Arnd Bergmann <[email protected]> > --- > arch/arm/common/locomo.c | 15 +++++++-------- > 1 file changed, 7 insertions(+), 8 deletions(-) > > diff --git a/arch/arm/common/locomo.c b/arch/arm/common/locomo.c > index 0e97b4b871f9..81abb04e5254 100644 > --- a/arch/arm/common/locomo.c > +++ b/arch/arm/common/locomo.c > @@ -253,8 +253,7 @@ locomo_init_one_child(struct locomo *lchip, struct > locomo_dev_info *info) > dev->mapbase = 0; > dev->length = info->length; > > - dev->irq[0] = (lchip->irq_base == NO_IRQ) ? > - NO_IRQ : lchip->irq_base + info->irq[0]; > + dev->irq[0] = lchip->irq_base + info->irq[0]; > > ret = device_register(&dev->dev); > if (ret) { > @@ -376,6 +375,9 @@ __locomo_probe(struct device *me, struct resource *mem, > int irq) > unsigned long r; > int i, ret = -ENODEV; > > + if (!pdata->irq_base) > + return ret; > + > lchip = kzalloc(sizeof(struct locomo), GFP_KERNEL); > if (!lchip) > return -ENOMEM; > @@ -387,7 +389,7 @@ __locomo_probe(struct device *me, struct resource *mem, > int irq) > > lchip->phys = mem->start; > lchip->irq = irq; > - lchip->irq_base = (pdata) ? pdata->irq_base : NO_IRQ; > + lchip->irq_base = pdata->irq_base; This removes a NULL pointer check. Before this change, a NULL pdata would be accepted and would lead to the interrupts not being setup. After this change, it results in a NULL pointer deference. Thankfully, both collie and poodle supply platform data, and are the only providers of the locomo device. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.
