Virtualization - Feb 2023 - [PATCH 17/17] drm/cirrus: Use VGA macro constants to unblank

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.

The PAS setting is actually part of the primary plane, so it's current 
location in the CRTC code is misleading. I didn't want to change the 
driver logic too much, but I guess I'll fix that in the next iteration.

Best regards
Thomas

[1] 
https://web.stanford.edu/class/cs140/projects/pintos/specs/freevga/vga/attrreg.htm#3C0
> 
> take care,
>    Gerd
> 
-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 N?rnberg, Germany
(HRB 36809, AG N?rnberg)
Gesch?ftsf?hrer: Ivo Totev
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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.
Yes, strictly speaking it is not the same thing. DPMS blank will send
the monitor into suspend mode which this does not.  On virtual hardware
there isn't much of a difference though ;)

take care,
  Gerd

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?

> 
> The PAS setting is actually part of the primary plane, so it's current 
> location in the CRTC code is misleading. I didn't want to change the 
> driver logic too much, but I guess I'll fix that in the next iteration.
> 
> Best regards
> Thomas
> 
> [1] 
>
https://web.stanford.edu/class/cs140/projects/pintos/specs/freevga/vga/attrreg.htm#3C0
> 
> > 
> > take care,
> >    Gerd
> > 
> 
> -- 
> Thomas Zimmermann
> Graphics Driver Developer
> SUSE Software Solutions Germany GmbH
> Maxfeldstr. 5, 90409 N?rnberg, Germany
> (HRB 36809, AG N?rnberg)
> Gesch?ftsf?hrer: Ivo Totev



-- 
Ville Syrj?l?
Intel