Re: [PATCH] OMAP: DSS: DPI: disable vt-switch on suspend/resume.
From: Pavel Machek
Date: Mon Mar 02 2015 - 16:04:03 EST
Hi!
> > Looking at the drivers/tty/vt/vt_ioctl.c, it sounds to me that we should
> > always do pm_set_vt_switch(0), as omapdss restores everything just fine
> > on resume. Although it makes me wonder how it works if there are two
> > display controllers, one needing the switch and the other not...
>
> I wondered that too. It would seem to make more sense for
> pm_set_vt_switch(0) to be the default, that drivers which need the textmode
> switch should call (1). But I suspect there are "historical reasons" for the
> current situation.
Well... historically, we did not have drivers for graphics cards --
kernel did not know how to handle it, only X knew. For cards that do
not have kernel driver, only X one, we need to switch vts.
For cards that have proper driver, we should be able to survive
without VT switch.
Pavel
--
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