Messages in this thread | | | Date | Tue, 31 Oct 2006 14:58:53 +0100 | From | "Miguel Ojeda" <> | Subject | Re: [PATCH 2.6.19-rc1 update4] drivers: add LCD support |
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On 10/31/06, Franck Bui-Huu <vagabon.xyz@gmail.com> wrote: > Miguel Ojeda wrote: > > Again: Please read LDD3. It explains it well. Read all the "Remapping > > RAM" chapter and you will understand what I've done, or just try to > > remap RAM yourself with remap_pfn_range. > > Well, I'm trying to get an explanation here and here is what I get > from you: > > MO > LDD3 states it must work like this. (Note: it doesn't explain > why though) > FBH > Weird I read the implementation of remap_pfn_range() and it > doesn't seem to have such restriction, I'm wondering how > things work... > MO > Again it's stated in LDD3, read again. > > Do you really think you explain anything with such replies ? >
Do you really think I have to explain anything with my replies? I was just trying to help you telling where I found the answer.
Anyway, isn't it explained in LDD3? isn't it stated in LDD3? I think it is (yep, not deeply, but enough: other books cover that points better and a device driver programmer doesn't have to know about implementations, right?). Sure, neither the book or I didn't know about the VM_PFNMAP change, but that doesn't change that I was trying to encourage you to read such chapter, the same way I found the answer there.
> > Fortunately, Hugh Dickins gives a hint and it appears that the > restriction doesn't hold anymore. > > > (I really tried it using > > different ways and I couldn't map it with remap_pfn_range, it returns > > you a place full with zeros, as LDD3 states). > > I'm really wondering how did you test the thing... ;) >
And I still say I tried it, many ways, using remap_pfn_range() and other weird things also. Finally, I thought something was wrong, so I read LDD3 and I found the explanation about why my code mmap couldn't mmap RAM. Also, my area was full of zeros, as LDD3 states. So I read a little further and I did what "Remapping RAM" explains.
Anything else?
Bye, Miguel Ojeda - 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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