Re: 8250.nr_uarts broken in 3.7

Jiri Slaby
2013-03-09T09:14:23Z

On 03/09/2013 12:44 AM, Josh Boyer wrote:
> On Fri, Mar 08, 2013 at 06:28:09PM -0500, Josh Boyer wrote:
>> On Sat, Mar 09, 2013 at 12:14:23AM +0100, Jiri Slaby wrote:
>>> On 03/09/2013 12:10 AM, Jiri Slaby wrote:
>>>> On 03/08/2013 11:58 PM, Jiri Slaby wrote:
>>>>> On 03/08/2013 11:49 PM, Josh Boyer wrote:
>>>>>> On Fri, Mar 08, 2013 at 11:47:01PM +0100, Jiri Slaby wrote:
>>>>>>> Yeah, I agree this is ugly. Just re-definining MODULE_PARAM_PREFIX at
>>>>>>> the end of the file should do the trick (followed by
>>>>>>> "module_param(nr_uarts, uint, 0644)").
>>>>>>
>>>>>> For some reason, I thought I had tried that. Maybe I didn't. I'll look
>>>>>> into it again.
>>>>>
>>>>> I see. Because we would re-define some global variables. What if we put
>>>>> module_param into a function?
>>>>
>>>> Something like this?
>>>> #ifdef MODULE
>>
>> I don't think you want this surrounded in #ifdef MODULE, do you? That
>> won't let people building the driver into the kernel continue to use
>> 8250.<whatever> on the kernel command line.

Yes, you're right. I sort of thought the prefix is not used for
non-modules. But it is.

>>>> static void __unused splat(void) {
>>>
>>> I meant __used. It should make no difference though.
>>>
>>>> # undef MODULE_PARAM_PREFIX
>>>> # define MODULE_PARAM_PREFIX "8250."
>>>> module_param_cb(nr_uarts, &param_ops_uint, &nr_uarts, 0644);
>>>> ...
>>>> }
>>>> #endif
>>>>
>>>> Not nice, but should work. The other way is to have those in a separate
>>>> file linked to 8250 (to avoid re-definition errors).
>>
>> Ew. I'll try the function first.
>
> OK, the function (without the surrounding ifdef) seems to be working OK.
> I'll do a bit more testing and send out a v2 in a bit.
>
> Thanks for the tip. It's still not pretty, but at least I don't feel
> ashamed about it.

I'm thinking about deprecating the 8250_core.* in some way. Better
sooner than later. The view of having both of them with that hack in the
kernel forever drives me bananas.

--
js
suse labs