Messages in this thread | | | Date | Tue, 21 May 2013 18:13:08 +0800 | From | Chen Gang <> | Subject | Re: [PATCH] arm64: kernel: need extern variable 'screen_info' for related driver using. |
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On 05/21/2013 05:03 PM, Will Deacon wrote: > On Tue, May 21, 2013 at 08:51:39AM +0100, Chen Gang wrote: >> On 05/21/2013 02:57 PM, Geert Uytterhoeven wrote: >>> On Tue, May 21, 2013 at 5:15 AM, Chen Gang <gang.chen@asianux.com> wrote: >>>>>>> I think it would be better if we added a something like >>>>>>> CONFIG_HAVE_VGA_CONSOLE, which VGA_CONSOLE can then depend on. Architectures >>>>>>> like x86 can then select the former, and we can remove the long list of >>>>>>> architectures from the current option. >>>>> >>>>> I guess your meaning is: >>>>> >>>>> under arm64, actually, need not support 'VGA_CONSOLE', and 'screen_info' is useless. >>>>> So better to define 'CONFIG_HAVE_VGA_CONSOLE' which 'VGA_CONSOLE' can depend on it, and in arm64, we do not define CONFIG_HAVE_VGA_CONSOLE. >>>>> >>>>> Is it correct ? >>> No, you missed "and we can remove the long list of architectures from the >>> current option". >>> >> >> OK, thanks. >> >> Is it correct: "it is unnecessary to add 'screen_info' to the code, for >> arm64 will never support 'VGA_CONSOLE'" ? > > We can add the screen_info if and when we need to support a VGA console. In > the meantime, let's not add things on a whim. >
OK, thanks. At least now (for our case), need not add 'screen_info', is it correct ?
>>>>> If so, I recommend to add depend item for VGA_CONSOLE directly: >>> I strongly support CONFIG_HAVE_VGA_CONSOLE. >> >> For me, I still recommend add 'ARM64' in the long list of architectures >> for 'VGA_CONSOLE', I have 3 reasons, please check: >> >> a. current implementation only changes one area which only related with >> arm64 and 'VGA_CONSOLE', but if use 'CONFIG_HAVE_VGA_CONSOLE', that will >> touch many multiple platforms dependency, at least we need discuss about >> it with multiple platforms guys for it, firstly. > > That's a weak argument. You might as well propose the cleanup and see what > people say. >
Hmm.. I think at least, we need discuss it with the 'final applier' firstly (and now, I even do not know who is the 'final applier').
>> b. We can find some cases to use CONFIG_HAVE_* as dpend on, but I can >> not find any cases which let CONFIG_'samename' depend on >> CONFIG_HAVE_'samename'. > > Erm. PERF_EVENTS, BPF_JIT, IDE, ...? >
CONFIG_PERF_EVENTS is not directly depend on CONFIG_HAVE_PERF_EVENTS. CONFIG_BPF_JIT is not directly depend on CONFIG_HAVE_BPF_JIT. CONFIG_IDE is not directly depend on CONFIG_HAVE_IDE. ...
But I guess what we will do is to let "CONFIG_VGA_CONSOLE is directly depend on CONFIG_HAVE_VGA_CONSOLE".
So I think we really need discuss it firstly with the 'final applier'.
>> c. The original way still has effect, although it seems not quit >> beautiful, but it is correct and still clear for readers, it is still >> sustainable. > > Sure, it works, but we're just contributing to the mess that's been built up > ever time another architecture has done the same thing. It's not hard to try > and clean it up. >
Can we separate into 2 patches ?. One is for current compiling issue with allmodconfig (the priority is a litter higher), the other is for fixup patch (the priority is lower). ;-)
BTW: In fact, if we really need send the related fixup patch, I am also unwilling to do that, I guess (in my experience), the fixup patch like that, will never be applied. :-(
Thanks. -- Chen Gang
Asianux Corporation
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