Messages in this thread |  | | | Date | Wed, 13 May 2009 16:02:35 -0600 | | From | Jonathan Corbet <> | | Subject | Re: [PATCH v2 5/7] [PATCH 5/8] can: SJA1000 generic platform bus driver |
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On Tue, 12 May 2009 11:28:02 +0200 Wolfgang Grandegger <wg@grandegger.com> wrote:
> This driver adds support for the SJA1000 chips connected to the > "platform bus", which can be found on various embedded systems.
[...]
> + > +static u8 sp_read_reg(const struct net_device *dev, int reg) > +{ > + return ioread8((void __iomem *)(dev->base_addr + reg)); > +} > + > +static void sp_write_reg(const struct net_device *dev, int reg, u8 val) > +{ > + iowrite8(val, (void __iomem *)(dev->base_addr + reg)); > +}
So there's no locking around accesses to the hardware at all. How do you protect against concurrent access?
[...]
> +static int sp_remove(struct platform_device *pdev) > +{ > + struct net_device *dev = dev_get_drvdata(&pdev->dev); > + struct resource *res; > + > + unregister_sja1000dev(dev); > + dev_set_drvdata(&pdev->dev, NULL); > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + release_mem_region(res->start, res->end - res->start + 1); > + > + if (dev->base_addr) > + iounmap((void __iomem *)dev->base_addr);
Seems like you should unmap it before releasing it back to the kernel. Nobody else is ever going to jump in and try to map it, but still...
> + free_sja1000dev(dev); > + > + return 0; > +}
jon
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