drm: Nuke mode->vrefresh

Get rid of mode->vrefresh and just calculate it on demand. Saves
a bit of space and avoids the cached value getting out of sync
with reality.

Mostly done with cocci, with the following manual fixups:
- Remove the now empty loop in drm_helper_probe_single_connector_modes()
- Fix __MODE() macro in ch7006_mode.c
- Fix DRM_MODE_ARG() macro in drm_modes.h
- Remove leftover comment from samsung_s6d16d0_mode
- Drop the TODO

@@
@@
struct drm_display_mode {
	...
-	int vrefresh;
	...
};

@@
identifier N;
expression E;
@@
struct drm_display_mode N = {
-	.vrefresh = E
};

@@
identifier N;
expression E;
@@
struct drm_display_mode N[...] = {
...,
{
-	.vrefresh = E
}
,...
};

@@
expression E;
@@
{
	DRM_MODE(...),
-	.vrefresh = E,
}

@@
identifier M, R;
@@
int drm_mode_vrefresh(const struct drm_display_mode *M)
{
  ...
- if (M->vrefresh > 0)
- 	R = M->vrefresh;
- else
  if (...) {
  ...
  }
  ...
}

@@
struct drm_display_mode *p;
expression E;
@@
(
- p->vrefresh = E;
|
- p->vrefresh
+ drm_mode_vrefresh(p)
)

@@
struct drm_display_mode s;
expression E;
@@
(
- s.vrefresh = E;
|
- s.vrefresh
+ drm_mode_vrefresh(&s)
)

@@
expression E;
@@
- drm_mode_vrefresh(E) ? drm_mode_vrefresh(E) : drm_mode_vrefresh(E)
+ drm_mode_vrefresh(E)

@find_substruct@
identifier X;
identifier S;
@@
struct X {
...
	struct drm_display_mode S;
...
};

@@
identifier find_substruct.S;
expression E;
identifier I;
@@
{
.S = {
-	.vrefresh = E
}
}

@@
identifier find_substruct.S;
identifier find_substruct.X;
expression E;
identifier I;
@@
struct X I[...] = {
...,
.S = {
-	.vrefresh = E
}
,...
};

v2: Drop TODO
v3: Rebase
v4: Rebase

Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Jernej Skrabec <jernej.skrabec@siol.net>
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Joonyoung Shim <jy0922.shim@samsung.com>
Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: CK Hu <ck.hu@mediatek.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jerry Han <hanxu5@huaqin.corp-partner.google.com>
Cc: Icenowy Zheng <icenowy@aosc.io>
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Stefan Mavrodiev <stefan@olimex.com>
Cc: Robert Chiras <robert.chiras@nxp.com>
Cc: "Guido Günther" <agx@sigxcpu.org>
Cc: Purism Kernel Team <kernel@puri.sm>
Cc: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Cc: Vincent Abriou <vincent.abriou@st.com>
Cc: VMware Graphics <linux-graphics-maintainer@vmware.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: linux-amlogic@lists.infradead.org
Cc: nouveau@lists.freedesktop.org
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200428171940.19552-4-ville.syrjala@linux.intel.com

1 files changed, 0 insertions, 20 deletions

diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
index 2ce52c5917f8..4c2b72f14316 100644
--- a/Documentation/gpu/todo.rst
+++ b/Documentation/gpu/todo.rst
@@ -327,26 +327,6 @@ Contact: Laurent Pinchart, Daniel Vetter
 Level: Intermediate (mostly because it is a huge tasks without good partial
 milestones, not technically itself that challenging)
 
-Convert direct mode.vrefresh accesses to use drm_mode_vrefresh()
-----------------------------------------------------------------
-
-drm_display_mode.vrefresh isn't guaranteed to be populated. As such, using it
-is risky and has been known to cause div-by-zero bugs. Fortunately, drm core
-has helper which will use mode.vrefresh if it's !0 and will calculate it from
-the timings when it's 0.
-
-Use simple search/replace, or (more fun) cocci to replace instances of direct
-vrefresh access with a call to the helper. Check out
-https://lists.freedesktop.org/archives/dri-devel/2019-January/205186.html for
-inspiration.
-
-Once all instances of vrefresh have been converted, remove vrefresh from
-drm_display_mode to avoid future use.
-
-Contact: Sean Paul
-
-Level: Starter
-
 connector register/unregister fixes
 -----------------------------------