Re: [PATCH] drivers: Let several drivers depends on HAS_IOMEM for 'devm_ioremap_resource'

From: Guenter Roeck
Date: Mon Jul 14 2014 - 20:53:16 EST

On 07/14/2014 05:34 PM, Chen Gang wrote:
On 07/14/2014 05:22 PM, Chen Gang wrote:

å 2014å7æ14æïäå4:57ïRichard Weinberger <richard@xxxxxx> åéï

Am 14.07.2014 10:48, schrieb Lars-Peter Clausen:
On 07/14/2014 10:31 AM, Richard Weinberger wrote:
Am 13.07.2014 22:17, schrieb Greg Kroah-Hartman:
On Sun, Jul 13, 2014 at 09:33:38PM +0200, Richard Weinberger wrote:
Maybe we could add COMPILE_TEST to the version string too?
Just to detect such kernels fast in user bug reports...

What kind of bug report are you going to get?

User manages to enable CONFIG_FOO by selecting COMPILE_TEST and
complains that it does not work. :)

These drivers are typically drivers for some SoC peripheral and the device will simply physically not exist on a platform that does not provide HAS_IOMEM. This is not really any
different from making the driver selectable via COMPILE_TEST for any other platform. To hit the issue you'd have to instantiate a device driver instance for a device that
physically does not exist. This will always result in a failure.

Okay, you have convinced me. :)

After search the history patches, I found one related patch which made
by myself (when I am in Asianux):


For me, it is a long discussion, and forced many members have to join
in. Please help check again.

One thing you could try would be to return NULL (or where appropriate
an error) in the #else case of CONFIG_HAS_IOMEM and CONFIG_HAS_IOPORT,
ie dont take COMPILE_TEST into account at all. Obviously that means
you won't be able to dump a warning message in the COMPILE_TEST
case, but at least the code would compile. The rejection of above patch
would make a good case for this approach.


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