Re: [PATCH] cyber2000fb: New framebuffer_alloc API and class_dev changes

Il Tue, Sep 16, 2003 at 02:44:59PM +0100, Russell King ha scritto: 

On Tue, Sep 16, 2003 at 03:40:09PM +0200, Kronos wrote:

quoted

Il Mon, Sep 15, 2003 at 11:58:32PM +0100, Russell King ha scritto: 

quoted

On Tue, Sep 16, 2003 at 12:17:42AM +0200, Kronos wrote:

quoted

Il Mon, Sep 15, 2003 at 10:40:42PM +0100, Russell King ha scritto: 

quoted

There is another reason why the above is fundamentally flawed - who says
that "release_cfb_info" will still be in module space by the time you
need to call it?

Eg, you unload your framebuffer driver module immediately after the device
has gone away, but someone is keeping the sysfs files associated with
the fb_info open.

I'm quite sure that this can't happen. If someone is keeping a sysfs
file open module use count won't be zero. Right?

Where are you handling the module use count of the framebuffer driver?

Every   attribute   (ie.  sysfs   file)   has   a  .owner   field   (see
include/linux/sysfs.h), the module  use count is handled  by sysfs. If a
sysfs file is open the module can't be unloaded.

The .owner field is set to the module which defined the sysfs attribute.
This wouldn't be the driver, but would be some other part of the framebuffer
layer.

Good point. I  was thinking  at files  created by  the driver  itself, I
forgot about  dev attribute. I  can overwrite  .owner of  dev attribute,
fbmem can't be built as module. Sounds good?

quoted

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Is there somewhere I can view the core changes?

They are on fbdev for review, I put a copy here:
http://web.tiscali.it/kronoz/linux/fbdev-class_dev-fbmem.c.diff

When I tried to get at the fbdev site, it seemed to be down.  Maybe
some of the kernel documentation needs to be updated?

Try here: http://linux-fbdev.sf.net
Mailing lists are here: http://linux-fbdev.sourceforge.net/mlist.html

Luca
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Home: http://kronoz.cjb.net
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