Re: Re: [PATCH 1/6] nvidiafb: ioremap and i2c fixes

["Randy.Dunlap" <rddunlap@osdl.org>]

On Sun, 24 Apr 2005 22:36:42 -0700 Miles Lane wrote:

| On 4/24/05, Randy.Dunlap <rddunlap@osdl.org> wrote:
| > On Mon, 25 Apr 2005 11:21:20 +0800 Antonino A. Daplas wrote:
| > 
| > | On Sunday 24 April 2005 08:40, Andrew Morton wrote:
| > | > "Antonino A. Daplas" <adaplas@hotpop.com> wrote:
| > | > > - Add 'vram' option to specify amount of video RAM to remap
| > | > >  - Limit remap size to 128 MIB
| > | >
| > | > Am I right in believing that if someone has a 256MB card and doesn't know
| > | > about the `vram' option, their card will fail to work, because the 128MB
| > | > vmalloc() will fail?
| > | >
| > |
| > | I thought that a 128MiB vmalloc will work.
| > 
| > The default vmalloc total size is 128 MB, but the kernel always
| > requires a "guard page", which cannot be allocated, so the
| > total allocation fails.
| > 
| > I tried to make a patch that sets the default vmalloc total size
| > to 128 MB + PAGE_SIZE, but Miles reported that the driver's
| > vmalloc() call still failed...
| 
| Which seems to beg a couple of questions:
| How much memory is _really_ trying to get allocated when I boot
| with no vmalloc argument.  Does this point to some problem in 
| the nvidiafb code?  Does the fact that specifying vmalloc=128M
| does not fix the problem indicate that something about my video
| card won't work with less than 256Mb vmalloced, or is this a
| driver issue?

or simply that some other code is also vmalloc-ing some memory,
so that nvidiafb's request can't succeed due to that?

You could go back to the very first test patch that I sent
to you to see if other vmalloc's are happening.  I don't recall
the result of that one, but it seems like it was "Nope."

---
~Randy


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