[Intel-gfx] [PATCH v3 4/7] drm/fb-helper: Apply panel orientation connector prop to the primary plane
Daniel Vetter
daniel at ffwll.ch
Tue Oct 31 10:40:58 UTC 2017
On Tue, Oct 31, 2017 at 11:24:14AM +0100, Hans de Goede wrote:
> Hi,
>
> On 31-10-17 11:14, Daniel Vetter wrote:
> > On Mon, Oct 30, 2017 at 12:09:27PM +0100, Hans de Goede wrote:
> > > Hi,
> > >
> > > On 30-10-17 10:52, Daniel Vetter wrote:
> > > > On Mon, Oct 23, 2017 at 09:14:22AM +0200, Hans de Goede wrote:
> > > > > Apply the "panel orientation" drm connector prop to the primary plane so
> > > > > that fbcon and fbdev using userspace programs display the right way up.
> > > > >
> > > > > Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=94894
> > > > > Signed-off-by: Hans de Goede <hdegoede at redhat.com>
> > > > > ---
> > > > > Changes in v2:
> > > > > -New patch in v2 of this patch-set
> > > > >
> > > > > Changes in v3:
> > > > > -Use a rotation member in struct drm_fb_helper_crtc and set that from
> > > > > drm_setup_crtcs instead of looping over all crtc's to find the right one
> > > > > later
> > > > > -Since we now no longer look at rotation quirks directly in the fbcon code,
> > > > > set fb_info.fbcon_rotate_hint when the panel is not mounted upright and
> > > > > we cannot use hardware rotation
> > > > > ---
> > > > > drivers/gpu/drm/drm_fb_helper.c | 76 +++++++++++++++++++++++++++++++++++++++--
> > > > > include/drm/drm_fb_helper.h | 8 +++++
> > > > > 2 files changed, 82 insertions(+), 2 deletions(-)
> > > > >
> > > > > diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> > > > > index 116d1f1337c7..e0f95f2cc52f 100644
> > > > > --- a/drivers/gpu/drm/drm_fb_helper.c
> > > > > +++ b/drivers/gpu/drm/drm_fb_helper.c
> > > > > @@ -41,6 +41,7 @@
> > > > > #include <drm/drm_atomic.h>
> > > > > #include <drm/drm_atomic_helper.h>
> > > > > +#include "drm_crtc_internal.h"
> > > > > #include "drm_crtc_helper_internal.h"
> > > > > static bool drm_fbdev_emulation = true;
> > > > > @@ -350,6 +351,7 @@ EXPORT_SYMBOL(drm_fb_helper_debug_leave);
> > > > > static int restore_fbdev_mode_atomic(struct drm_fb_helper *fb_helper, bool active)
> > > > > {
> > > > > struct drm_device *dev = fb_helper->dev;
> > > > > + struct drm_plane_state *plane_state;
> > > > > struct drm_plane *plane;
> > > > > struct drm_atomic_state *state;
> > > > > int i, ret;
> > > > > @@ -368,8 +370,6 @@ static int restore_fbdev_mode_atomic(struct drm_fb_helper *fb_helper, bool activ
> > > > > retry:
> > > > > plane_mask = 0;
> > > > > drm_for_each_plane(plane, dev) {
> > > > > - struct drm_plane_state *plane_state;
> > > > > -
> > > > > plane_state = drm_atomic_get_plane_state(state, plane);
> > > > > if (IS_ERR(plane_state)) {
> > > > > ret = PTR_ERR(plane_state);
> > > > > @@ -392,6 +392,11 @@ static int restore_fbdev_mode_atomic(struct drm_fb_helper *fb_helper, bool activ
> > > > > for (i = 0; i < fb_helper->crtc_count; i++) {
> > > > > struct drm_mode_set *mode_set = &fb_helper->crtc_info[i].mode_set;
> > > > > + struct drm_plane *primary = mode_set->crtc->primary;
> > > > > +
> > > > > + /* Cannot fail as we've already gotten the plane state above */
> > > > > + plane_state = drm_atomic_get_new_plane_state(state, primary);
> > > > > + plane_state->rotation = fb_helper->crtc_info[i].rotation;
> > > > > ret = __drm_atomic_helper_set_config(mode_set, state);
> > > > > if (ret != 0)
> > > > > @@ -2334,6 +2339,57 @@ static int drm_pick_crtcs(struct drm_fb_helper *fb_helper,
> > > > > return best_score;
> > > > > }
> > > > > +/*
> > > > > + * This function checks if rotation is necessary because of panel orientation
> > > > > + * and if it is, if it is supported.
> > > > > + * If rotation is necessary and supported, its gets set in fb_crtc.rotation.
> > > > > + * If rotation is necessary but not supported, a DRM_MODE_ROTATE_* flag gets
> > > > > + * or-ed into fb_helper->rotations. In drm_setup_crtcs_fb() we check if only
> > > > > + * one bit is set and then we set fb_info.fbcon_rotate_hint to make fbcon do
> > > > > + * the unsupported rotation.
> > > > > + */
> > > > > +static void drm_setup_crtc_rotation(struct drm_fb_helper *fb_helper,
> > > > > + struct drm_fb_helper_crtc *fb_crtc,
> > > > > + struct drm_connector *connector)
> > > > > +{
> > > > > + struct drm_plane *plane = fb_crtc->mode_set.crtc->primary;
> > > > > + uint64_t valid_mask = 0;
> > > > > + int i, rotation;
> > > > > +
> > > > > + fb_crtc->rotation = DRM_MODE_ROTATE_0;
> > > > > +
> > > > > + switch (connector->display_info.panel_orientation) {
> > > > > + case DRM_MODE_PANEL_ORIENTATION_BOTTOM_UP:
> > > > > + rotation = DRM_MODE_ROTATE_180;
> > > > > + break;
> > > > > + case DRM_MODE_PANEL_ORIENTATION_LEFT_UP:
> > > > > + rotation = DRM_MODE_ROTATE_90;
> > > > > + break;
> > > > > + case DRM_MODE_PANEL_ORIENTATION_RIGHT_UP:
> > > > > + rotation = DRM_MODE_ROTATE_270;
> > > > > + break;
> > > >
> > > > For 90/270 hw rotation you need to flip the coordinates/sizes of the fb.
> > >
> > > You're probably right, I don't have any hardware supporting
> > > 270 degree rotation to test this with.
> > >
> > > > > + default:
> > > > > + rotation = DRM_MODE_ROTATE_0;
> > > > > + }
> > > > > +
> > > > > + if (rotation == DRM_MODE_ROTATE_0 || !plane->rotation_property) {
> > > > > + fb_helper->rotations |= rotation;
> > > > > + return;
> > > > > + }
> > > > > +
> > > > > + for (i = 0; i < plane->rotation_property->num_values; i++)
> > > > > + valid_mask |= (1ULL << plane->rotation_property->values[i]);
> > > >
> > > > This isn't a good enough check for atomic drivers (and not for gen9+ intel
> > > > hw), since we might expose 90° rotations, but it only works if you have
> > > > the correct tiling format.
> > > >
> > > > For atomic drivers it'd be really good if we could do a TEST_ONLY commit
> > > > first, and if that fails, fall back to sw rotation.
> > > >
> > > > But that poses a bit a chicken&egg with creating the framebuffer (we need
> > > > one for the TEST_ONLY), so probably a bit too much more for this. And
> > > > afaiui your quirk list only applies to older stuff.
> > > >
> > > > At least add a FIXME meanwhile? In a way we have a FIXME already for
> > > > multi-pipe, since we don't try to fall back to fewer pipes if the single
> > > > atomic commit failed.
> > > >
> > > > Or maybe just don't use 90/270 hw rotation for now since it seems buggy in
> > > > your code anyway.
> > >
> > > I was wondering about this (need for special fb layout) myself too, I
> > > agree also given the above comment that it is probably best to only
> > > support 0/180 degree hardware rotation for now, I will do for the next
> > > version (and add a TODO comment).
> >
> > It'll work on i915 at least, on current hw. Might still be broken on
> > other, but then that's a larger issue with the fbcon atomic code right
> > now.
> > >
> > >
> > > > > +
> > > > > + if (!(rotation & valid_mask)) {
> > > > > + fb_helper->rotations |= rotation;
> > > > > + return;
> > > > > + }
> > > > > +
> > > > > + fb_crtc->rotation = rotation;
> > > > > + /* Rotating in hardware, fbcon should not rotate */
> > > > > + fb_helper->rotations |= DRM_MODE_ROTATE_0;
> > > >
> > > > Wrong bitopt I think.
> > >
> > > No this is intentional, if we've a panel requiring say 90 degree rotation
> > > which we will do in software and another panel (weird example) doing 180
> > > degree rotation in hardware, then we want to or both
> > > DRM_MODE_ROTATE_90 and DRM_MODE_ROTATE_0 into the rotations bitmask
> > > (0 since the hardware rotation requires no sw rotation).
> > > The rotations bitmask is the *combination* of all rotations we need
> > > fbcon to do in software and when that ends up being more then one
> > > rotation we chicken out and just don't do any software rotation,
> > > maybe I should rename rotations to sw_rotations?
> > >
> > > A better real world example is a 90 degree rotated panel with
> > > an external monitor, in that case for the panel we hit:
> > >
> > > if (!(rotation & valid_mask)) {
> > > fb_helper->rotations |= rotation;
> > > return;
> > > }
> > >
> > > Or-ing in the panel's DRM_MODE_ROTATE_90.
> > >
> > > And for the monitor we hit:
> > >
> > > if (rotation == DRM_MODE_ROTATE_0 || !plane->rotation_property) {
> > > fb_helper->rotations |= rotation;
> > > return;
> > > }
> > >
> > > Or-ing in the monitors's DRM_MODE_ROTATE_0.
> > >
> > > So we end up with 2 bits set in fb_helper->rotations, hitting the
> > > default in the switch case and picking FB_ROTATE_UR, since we cannot
> > > satisfy both rotations in fbcon at the same time.
> > >
> > >
> > > > Or you're doing some really funny control logic by oring in another value
> > > > to hit the default case below which doesn't rotate anything. I think that
> > > > should be done explicitly, by explicitly setting to rotation to ROTATE_0
> > > > instead of this. Same for the check above.
> > >
> > > I hope my explanation above explains why I'm or-ing together rotations,
> > > basically I want to detect if we need more then 1 type of software-rotation
> > > in fbcon and in that case bail out and fallback to FB_ROTATE_UR.
> >
> > Yeah I suspected this is what you're trying to do, but imo it's too clear.
> > Can't we do an explicit check for this instead of uncommented magic
>
> Erm, my patch contains a big(ish) comment above drm_setup_crtc_rotation which
> tries to explain this already.
> > that takes half an hour to understand? I'm thinking of
> >
> > if (count_bits(fbb_helper->rotation)) {
> > /* conflicting rotation requests on different connnectors, fall
> > * back to unrotated. */
> >
> > fb_helper->rotation == ROTATE_0
> > }
> >
> > Or something similar at the end of drm_setup_crtcs (plus maybe doing the
> > resolve in there too). Right now that logic is split between 2 functions,
> > and no comment explaining what's going on.
> >
> > But not sure that's actually going to help with readability.
>
> I was thinking of just changing the code setting the fbcon_rotate_hint
> to something like this:
>
> switch (fb_helper->sw_rotations) {
> case DRM_MODE_ROTATE_0:
> info->fbcon_rotate_hint = FB_ROTATE_UR;
> break;
> case DRM_MODE_ROTATE_90:
> info->fbcon_rotate_hint = FB_ROTATE_CCW;
> break;
> case DRM_MODE_ROTATE_180:
> info->fbcon_rotate_hint = FB_ROTATE_UD;
> break;
> case DRM_MODE_ROTATE_270:
> info->fbcon_rotate_hint = FB_ROTATE_CW;
> break;
> default:
> /*
> * Multiple bits are set / multiple rotations requested
> * fbcon cannot handle separate rotation settings per
> * output, so fallback to unrotated.
> */
> info->fbcon_rotate_hint = FB_ROTATE_UR;
> }
>
> Would that work for you ?
Ack.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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