Re: [Linux-fbdev-devel] fbmem: is bootup logo broken for monochromeLCD ?

From: James Simmons
Date: Mon Nov 27 2006 - 11:02:46 EST

> > Replace the below line in my patch I sent
> >
> > > > val |= color << shift;
> >
> > with
> > val <<= shift;
> > val |= color;
> I think it can't work since shift is 0 to 31, you'll end up with 'val
> <<= 31' which I don't think is what you want.

> doing
> val <<= 1;
> make it works but it's still very fragile. Code which deals with
> trailing bit seems bogus since new value of 'val' is simply discarded
> here.

I'm going to test the code in depth over the next few days. I managed to
fix most of the problems with fast_imageblit. Now to fix the slow image
blit code.

> I'm wondering if working with 32 bits words really worth... I mean the
> code is quite hard to follow because it needs to deal with endianess,
> heading bits, trailings bits whereas working with 8 bits would be so
> much easier, wouldn't it ? Are writings in video RAM very long ?

Yes. We need to minimize the writes over the PCI bus. Its really really
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