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Subject: Re: [Linux-fbdev-devel] [BK FBDEV] A few more updates.
From: Antonino Daplas <adaplas@pol.net>
To: James Simmons <jsimmons@infradead.org>
Cc: Linux Fbdev development list 
	<linux-fbdev-devel@lists.sourceforge.net>,
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On Wed, 2003-03-26 at 13:34, James Simmons wrote:
> 
> > 3.  BTW, there are too many kmalloc's/kfree's in accel_cursor() and
> > softcursor().  Personally, I would rather have 2 64-byte buffers for the
> > mask and the data in the info->cursor structure than allocating/freeing
> > memory each time the cursor flashes.  However, if you prefer doing it
> > this way, the patch also includes changes so kmallocs are only done when
> > necessary.  Still, accel_cursor() has unnecessary work being done, such
> > as always creating the mask bitmap, when a simple flag to monitor cursor
> > shape changes could prevent all this.
> 
> I agree. The problem is the upper layer of the console system is to brain 
> dead. Its either erase the cursor or redraw it again. There is no way to 
> just say cursor just moved. There is a CM_MOVE but the upper layer doesn't 
> even use it :-( If you look at vgacon and friends you will see they 
> recreate the cursor every time the cursor blinks. Yes even vgacon.c does 
> this. It is stupid and brain dead but that is the way the upper layers of 
> the console work. The correct solution would be to use actually use 
> CM_MOVE in the upper layers.

Even so, (and I don't really fault the console cursor as it only needs
to show, hide and move the cursor), accel_cursor() can easily monitor
shape changes.  We can use a bitfield somewhere in fb_cursor(perhaps the
high 8 bits of info->fb_cursor.set?) to "remember" the current cursor
shape.

Tony


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