Re: [PATCH 3/5] drm,kdb,kms: Add an enter argument tomode_set_base_atomic() API

From: Jesse Barnes
Date: Tue Oct 12 2010 - 11:53:06 EST


On Tue, 12 Oct 2010 10:46:52 -0500
Jason Wessel <jason.wessel@xxxxxxxxxxxxx> wrote:

> On 10/12/2010 10:38 AM, Jesse Barnes wrote:
> > On Tue, 12 Oct 2010 07:49:59 -0500
> > Jason Wessel <jason.wessel@xxxxxxxxxxxxx> wrote:
> >
> >
> >> Some devices such as the pre nv02 chips have enter and exit
> >> constraints where hardware compression must be turned off and
> >> re-enabled on resuming normal operations.
> >>
> >> This patch extends the mode_set_base_atomic() call to pass an argument
> >> to indicate if this is an entry or an exit from an atomic kernel mode
> >> set change. Individual drm drivers can properly save and restore
> >> state accordingly.
> >>
> >> Signed-off-by: Jason Wessel <jason.wessel@xxxxxxxxxxxxx>
> >> CC: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
> >> CC: David Airlie <airlied@xxxxxxxx>
> >> CC: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> >> ---
> >> drivers/gpu/drm/drm_fb_helper.c | 5 +++--
> >> drivers/gpu/drm/i915/intel_display.c | 4 ++--
> >> drivers/gpu/drm/nouveau/nv04_crtc.c | 2 +-
> >> drivers/gpu/drm/nouveau/nv50_crtc.c | 2 +-
> >> drivers/gpu/drm/radeon/atombios_crtc.c | 2 +-
> >> drivers/gpu/drm/radeon/radeon_legacy_crtc.c | 2 +-
> >> drivers/gpu/drm/radeon/radeon_mode.h | 4 ++--
> >> include/drm/drm_crtc_helper.h | 3 ++-
> >> 8 files changed, 13 insertions(+), 11 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> >> index 6a5e403..625a2d5 100644
> >> --- a/drivers/gpu/drm/drm_fb_helper.c
> >> +++ b/drivers/gpu/drm/drm_fb_helper.c
> >> @@ -263,7 +263,8 @@ int drm_fb_helper_debug_enter(struct fb_info *info)
> >> funcs->mode_set_base_atomic(mode_set->crtc,
> >> mode_set->fb,
> >> mode_set->x,
> >> - mode_set->y);
> >> + mode_set->y,
> >> + 1);
> >>
> >
> > An enum for the last arg would make this call much less mysterious. :)
> >
> >
> Is there anything that is already predefined or would you prefer just
> true or false?
>
> This could be changed to a bool because there are really only two
> states, entering and exiting. If you provide some guidance on the
> preferred naming, I can re-spin the patch.

I was thinking:

enum mode_set_atomic {
ENTER_KDB,
EXIT_KDB,
};

or something similar (the name of the enum could probably be better).
Just having a number or true/false always makes me have to check the
function prototype. Having an enum means it's readable at the
callsite. But this is really just a nitpick; bool args like this are a
pet peeve of mine. :)

--
Jesse Barnes, Intel Open Source Technology Center
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