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

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 

> > 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 
slow.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/
[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux