On Thu, Feb 16, 2023 at 02:21:43PM +0100, Thomas Zimmermann wrote: > Hi > > Am 16.02.23 um 13:52 schrieb Ville Syrjälä: > > On Thu, Feb 16, 2023 at 01:03:02PM +0100, Thomas Zimmermann wrote: > >> Hi, > >> > >> thanks for taking a look at the patches. > >> > >> Am 16.02.23 um 12:33 schrieb Gerd Hoffmann: > >>> On Wed, Feb 15, 2023 at 05:15:17PM +0100, Thomas Zimmermann wrote: > >>>> Set the VGA bit for unblanking with macro constants instead of magic > >>>> values. No functional changes. > >>> > >>> blank/unblank should work simliar to bochs (see commit 250e743915d4), > >>> that is maybe a nice thing to add of you modernize the driver anyway. > >> Yeah, it's the VGA PAS field. [1] But is it really called blanking? PAS > >> controls palette access, but blanking is sounds more like DPMS. > > > > Why aren't people just using the normal way of flipping the > > screen off bit in sequencer register 01? > > Setting the SD bit in SR01 isn't a bad idea. We can do this as part of > enabling/disabling the plane. > > But for PAS, we don't have a choice. It's one of the bazillion obscure > VGA settings and (according to a comment in the source code) we need to > update it for compatibility. Well, you do need to enable the palette to see something other that border color. Not sure tha't a very obscure thing :P On a related note, the code looks pretty sketchy. It just blindly writes to 0x3c0 assuming it is the attribute controller index register. But unless you explicitly reset the flip-flop it could actually be the data write register instead. That could easily happen if the previous access to the attribute controller was a read since reads do not toggle the register role. -- Ville Syrjälä Intel
