Messages in this thread | | | Date | Wed, 21 Sep 2005 20:17:38 +0100 | From | Russell King <> | Subject | Re: [PATCH] Au1x00 8250 uart support (Updated - take #2). |
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On Wed, Sep 21, 2005 at 07:14:09PM +0300, Pantelis Antoniou wrote: > > This is also buggy - the problem this has is that although you're > > unregistering the platform device, references can still remain after > > the module has been unloaded. This means you have two options: > > > > 1. never allow code with statically allocated platform devices to be > > modules. > > 2. use something like platform_device_register_simple() (which doesn't > > currently exist in a useful form for devices with platform data.) > > > > Yes, this is stinking mess. I resorted to just not allowing a module build. > > BTW, the current platform_device_register_simple suffers from the same bug. > > ! struct platform_device *platform_device_register_simple(char *name, unsigned int id, > ! struct resource *res, unsigned int num) > ! > > later on in the function body we have... > > ! pobj->pdev.name = name; > > It's clearly buggy, since the typical calling sequence passes a constant > string as a 'name' argument, which is located in the read only segment > of the module (.text or .rodata). > > To fix this space for the name must be allocated just like the resources...
Is this true? platform_device_register uses pdev.name to construct the bus id. pdev.name is also used when matching against drivers.
However, once a platform device is unregistered, it is no longer available to be matched against drivers, so pdev.name is unused. Therefore, I don't think this is a problem.
> +#ifdef CONFIG_SERIAL_8250_AU1X00_MODULE > +#error This file can not yet be compiled as a module. > +#endif
This isn't how we prevent modular builds...
> diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig > --- a/drivers/serial/Kconfig > +++ b/drivers/serial/Kconfig > @@ -207,6 +207,14 @@ config SERIAL_8250_ACORN > system, say Y to this option. The driver can handle 1, 2, or 3 port > cards. If unsure, say N. > > +config SERIAL_8250_AU1X00 > + tristate "AU1X00 serial port support"
We prevent them by setting this to 'bool'.
> + depends on SOC_AU1X00 && SERIAL_8250
It doens't really depend on SERIAL_8250 - it can live independently of it. However, it can be built in when SERIAL_8250 isn't, so this dependency should be SERIAL_8250 != n.
-- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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