Re: [PATCH v10 2/2] tty/serial: Add Spreadtrum sc9836-uart driver support

[Peter Hurley <peter@hurleysoftware.com>]

On 01/30/2015 10:49 AM, Russell King - ARM Linux wrote:
> On Fri, Jan 30, 2015 at 10:32:54AM -0500, Peter Hurley wrote:
>> Before you say consistency, I think you should look at the stats below.
>> IOW, if you want to change the error code return from probe() for
>> consistency's sake, a tree-wide patch would be the appropriate way.
> 
> Now look outside the serial driver sub-tree.
> 
> There are 1234 instances of platform_get_resource(, IORESOURCE_MEM, ) in
> the drivers/ sub-tree, with 700 instances of devm_ioremap_resource()
> being used there.  Of the devm_ioremap_resource() instances:
> 
> - 555 use platform_get_resource() in the preceding two lines - which is
>   not enough to do anything but rely on the -EINVAL return value.
> - 16 mention ENODEV in the preceding three lines.
> 
> There are 132 which use platform_get_resource() and return ENODEV within
> the following three lines (which may intersect with the above 16 number)
> and 88 which use EINVAL.
> 
> So, there are in total 643 instances where a missing resource returns
> EINVAL, and between 132 and 148 instances which return ENODEV.
> 
> Yes, 643 + 148 isn't 1234, but I'm not going to read through all 1234
> locations just for the sake of this thread.   What's clear though is that
> more than 50% of sites using platform_get_resource(, IORESOURCE_MEM, )
> return EINVAL for the lack of a resource.

Sure, now that they're using devm_ioremap_resource(). What about before
they were converted?

For example, of the 10 serial drivers now using devm_ioremap_resource(),
_not 1 returned EINVAL_ prior to using devm_ioremap_resource(). And of those
10 commits, only 1 mentions changing the return codes on purpose.

In fact, all of them but one returned ENODEV.

Regards,
Peter Hurley