Messages in this thread | | | Date | Mon, 10 Mar 2008 16:24:07 -0600 | From | Jordan Crouse <> | Subject | Re: PM/FB/gxfb: add config option that allows disabling of VT switch during suspend |
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On 10/03/08 18:14 -0400, Andres Salomon wrote: > On Mon, 10 Mar 2008 14:51:18 -0700 > Andrew Morton <akpm@linux-foundation.org> wrote: > > > On Mon, 10 Mar 2008 17:44:24 -0400 > > Andres Salomon <dilinger@queued.net> wrote: > > > > > On Mon, 10 Mar 2008 14:19:39 -0700 > > > Andrew Morton <akpm@linux-foundation.org> wrote: > > > > > > > > > > > It would be far preferable to do this via a kernel boot parameter rather > > > > than via a kernel rebuild. > > > > > > > > > > Well, it shouldn't be supported at _all_ unless the framebuffer driver > > > supports it; you're asking for it to be converted to something like the > > > following? > > > > > > > > > > > > #ifdef CONFIG_FBDEV_SUPPORTS_NOSWITCH > > > static int no_vt_switch; > > > #endif > > > > > > int pm_prepare_console(void) > > > { > > > #ifdef CONFIG_FBDEV_SUPPORTS_NOSWITCH > > > if (no_vt_switch) > > > return 0; > > > #endif > > > ... > > > } > > > > > > #ifdef CONFIG_FBDEV_SUPPORTS_NOSWITCH > > > module_param(no_vt_switch, int, 0); > > > MODULE_PARM_DESC(no_vt_switch, "..."); > > > #endif > > > > > > > > > If so, that means extra #ifdef's sprinkled throughout the code. Note > > > that most framebuffer drivers won't be supporting this, and those that > > > do will almost certainly always want vt switching turned off.. > > > > > > > I don't think you need any ifdefs or config options at all, do you? Just > > add a new module parameter to this driver and some little interface into > > the PM core which allows the driver to set no_vt_switch? > > > > That's a possibility, but doesn't adding hooks into PM core for two > drivers (lxfb and gxfb) seems like overkill? I also don't really see > anyone needing to switch back and forth between VT_SWITCH and > NO_VT_SWITCH other than to work around possible bugs in the register > save/restore code..
I like Andrew's idea. I wager This won't be Geode specific for long. Either other drivers will get the hint and add real save/restore code or the GPU subystem code being worked on by the X folks will come along and make the VT switch obsolete for everybody. Either way, I see hooks in the PM core as generic love that everybody can benefit from.
Jordan
-- Jordan Crouse Systems Software Development Engineer Advanced Micro Devices, Inc.
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