From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <mripard@kernel.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>
Cc: Helge Deller <deller@gmx.de>,
Michael Schmitz <schmitzmic@gmail.com>,
dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org,
linux-m68k@vger.kernel.org, linux-kernel@vger.kernel.org,
Geert Uytterhoeven <geert@linux-m68k.org>
Subject: [PATCH/RFC 2/3] drm/simple-kms-helper: Add mode_fixup() to simple display pipe
Date: Fri, 25 Nov 2022 21:31:09 +0100 [thread overview]
Message-ID: <3b0862187f1c8910089cb0d06a8669caa985042e.1669406382.git.geert@linux-m68k.org> (raw)
In-Reply-To: <cover.1669406380.git.geert@linux-m68k.org>
From: Thomas Zimmermann <tzimmermann@suse.de>
The mode fix-up function for simple display helpers is equivalent to the
regular pipeline's CRTC mode fix-up function. It's called to adjust the
CRTC's display mode for the encoder. Add this function for DRM fbconv
helpers.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
drivers/gpu/drm/drm_simple_kms_helper.c | 15 +++++++++
include/drm/drm_simple_kms_helper.h | 43 +++++++++++++++++++++++++
2 files changed, 58 insertions(+)
diff --git a/drivers/gpu/drm/drm_simple_kms_helper.c b/drivers/gpu/drm/drm_simple_kms_helper.c
index 3ef420ec4534aab5..3d7f859ac9de6814 100644
--- a/drivers/gpu/drm/drm_simple_kms_helper.c
+++ b/drivers/gpu/drm/drm_simple_kms_helper.c
@@ -96,6 +96,20 @@ drm_simple_kms_crtc_mode_valid(struct drm_crtc *crtc,
return pipe->funcs->mode_valid(pipe, mode);
}
+static bool
+drm_simple_kms_crtc_mode_fixup(struct drm_crtc *crtc,
+ const struct drm_display_mode *mode,
+ struct drm_display_mode *adjusted_mode)
+{
+ struct drm_simple_display_pipe *pipe;
+
+ pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
+ if (!pipe->funcs || !pipe->funcs->mode_fixup)
+ return true;
+
+ return pipe->funcs->mode_fixup(crtc, mode, adjusted_mode);
+}
+
static int drm_simple_kms_crtc_check(struct drm_crtc *crtc,
struct drm_atomic_state *state)
{
@@ -141,6 +155,7 @@ static void drm_simple_kms_crtc_disable(struct drm_crtc *crtc,
static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
.mode_valid = drm_simple_kms_crtc_mode_valid,
+ .mode_fixup = drm_simple_kms_crtc_mode_fixup,
.atomic_check = drm_simple_kms_crtc_check,
.atomic_enable = drm_simple_kms_crtc_enable,
.atomic_disable = drm_simple_kms_crtc_disable,
diff --git a/include/drm/drm_simple_kms_helper.h b/include/drm/drm_simple_kms_helper.h
index 2298fe3af4cd7abb..2312d089ae85a2b6 100644
--- a/include/drm/drm_simple_kms_helper.h
+++ b/include/drm/drm_simple_kms_helper.h
@@ -52,6 +52,49 @@ struct drm_simple_display_pipe_funcs {
enum drm_mode_status (*mode_valid)(struct drm_simple_display_pipe *pipe,
const struct drm_display_mode *mode);
+ /**
+ * @mode_fixup:
+ *
+ * This callback is used to validate a mode. The parameter mode is the
+ * display mode that userspace requested, adjusted_mode is the mode the
+ * encoders need to be fed with. Note that this is the inverse semantics
+ * of the meaning for the &drm_encoder and &drm_bridge_funcs.mode_fixup
+ * vfunc. If the CRTC of the simple display pipe cannot support the
+ * requested conversion from mode to adjusted_mode it should reject the
+ * modeset.
+ *
+ * This function is optional.
+ *
+ * NOTE:
+ *
+ * This function is called in the check phase of atomic modesets, which
+ * can be aborted for any reason (including on userspace's request to
+ * just check whether a configuration would be possible). Atomic drivers
+ * MUST NOT touch any persistent state (hardware or software) or data
+ * structures except the passed in adjusted_mode parameter.
+ *
+ * Atomic drivers which need to inspect and adjust more state should
+ * instead use the @atomic_check callback, but note that they're not
+ * perfectly equivalent: @mode_valid is called from
+ * drm_atomic_helper_check_modeset(), but @atomic_check is called from
+ * drm_atomic_helper_check_planes(), because originally it was meant for
+ * plane update checks only.
+ *
+ * Also beware that userspace can request its own custom modes, neither
+ * core nor helpers filter modes to the list of probe modes reported by
+ * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure
+ * that modes are filtered consistently put any CRTC constraints and
+ * limits checks into @mode_valid.
+ *
+ * RETURNS:
+ *
+ * True if an acceptable configuration is possible, false if the modeset
+ * operation should be rejected.
+ */
+ bool (*mode_fixup)(struct drm_crtc *crtc,
+ const struct drm_display_mode *mode,
+ struct drm_display_mode *adjusted_mode);
+
/**
* @enable:
*
--
2.25.1
next prev parent reply other threads:[~2022-11-25 20:31 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-25 20:31 [PATCH/RFC 0/3] Atari DRM driver Geert Uytterhoeven
2022-11-25 20:31 ` [PATCH/RFC 1/3] video: fbdev: c2p: Add transp2() and transp2x() Geert Uytterhoeven
2022-11-25 20:31 ` Geert Uytterhoeven [this message]
2022-11-28 8:21 ` [PATCH/RFC 2/3] drm/simple-kms-helper: Add mode_fixup() to simple display pipe Maxime Ripard
2022-11-25 20:31 ` [PATCH/RFC 3/3] drm: atari: Add a DRM driver for Atari graphics hardware Geert Uytterhoeven
2022-11-26 14:51 ` Thomas Zimmermann
2022-11-28 13:08 ` Geert Uytterhoeven
2022-11-28 8:28 ` Maxime Ripard
2023-01-23 15:03 ` [PATCH/RFC 0/3] Atari DRM driver John Paul Adrian Glaubitz
2023-01-23 15:10 ` Geert Uytterhoeven
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