[PATCH 5.14 159/169] drm/kmb: Limit supported mode to 1080p

Greg Kroah-Hartman
2021-10-25T19:58:58Z

From: Anitha Chrisanthus <anitha.chrisanthus@intel.com>

[ Upstream commit a79f40cccd4644c32f6d5ae1ccf091a262e1dc57 ]

KMB only supports single resolution(1080p), this commit checks for
1920x1080x60 or 1920x1080x59 in crtc_mode_valid.
Also, modes with vfp < 4 are not supported in KMB display. This change
prunes display modes with vfp < 4.

v2: added vfp check

Fixes: 7f7b96a8a0a1 ("drm/kmb: Add support for KeemBay Display")
Co-developed-by: Edmund Dea <edmund.j.dea@intel.com>
Signed-off-by: Edmund Dea <edmund.j.dea@intel.com>
Signed-off-by: Anitha Chrisanthus <anitha.chrisanthus@intel.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link:https://patchwork.freedesktop.org/patch/msgid/20211013233632.471892-2-anitha.chrisanthus@intel.com
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/kmb/kmb_crtc.c | 34 ++++++++++++++++++++++++++++++++++
drivers/gpu/drm/kmb/kmb_drv.h | 9 ++++++++-
2 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/kmb/kmb_crtc.c b/drivers/gpu/drm/kmb/kmb_crtc.c
index 4f240466cf63..06613ffeaaf8 100644
--- a/drivers/gpu/drm/kmb/kmb_crtc.c
+++ b/drivers/gpu/drm/kmb/kmb_crtc.c
@@ -186,11 +186,45 @@ static void kmb_crtc_atomic_flush(struct drm_crtc *crtc,
spin_unlock_irq(&crtc->dev->event_lock);
}

+static enum drm_mode_status
+ kmb_crtc_mode_valid(struct drm_crtc *crtc,
+ const struct drm_display_mode *mode)
+{
+ int refresh;
+ struct drm_device *dev = crtc->dev;
+ int vfp = mode->vsync_start - mode->vdisplay;
+
+ if (mode->vdisplay < KMB_CRTC_MAX_HEIGHT) {
+ drm_dbg(dev, "height = %d less than %d",
+ mode->vdisplay, KMB_CRTC_MAX_HEIGHT);
+ return MODE_BAD_VVALUE;
+ }
+ if (mode->hdisplay < KMB_CRTC_MAX_WIDTH) {
+ drm_dbg(dev, "width = %d less than %d",
+ mode->hdisplay, KMB_CRTC_MAX_WIDTH);
+ return MODE_BAD_HVALUE;
+ }
+ refresh = drm_mode_vrefresh(mode);
+ if (refresh < KMB_MIN_VREFRESH || refresh > KMB_MAX_VREFRESH) {
+ drm_dbg(dev, "refresh = %d less than %d or greater than %d",
+ refresh, KMB_MIN_VREFRESH, KMB_MAX_VREFRESH);
+ return MODE_BAD;
+ }
+
+ if (vfp < KMB_CRTC_MIN_VFP) {
+ drm_dbg(dev, "vfp = %d less than %d", vfp, KMB_CRTC_MIN_VFP);
+ return MODE_BAD;
+ }
+
+ return MODE_OK;
+}
+
static const struct drm_crtc_helper_funcs kmb_crtc_helper_funcs = {
.atomic_begin = kmb_crtc_atomic_begin,
.atomic_enable = kmb_crtc_atomic_enable,
.atomic_disable = kmb_crtc_atomic_disable,
.atomic_flush = kmb_crtc_atomic_flush,
+ .mode_valid = kmb_crtc_mode_valid,
};

int kmb_setup_crtc(struct drm_device *drm)
diff --git a/drivers/gpu/drm/kmb/kmb_drv.h b/drivers/gpu/drm/kmb/kmb_drv.h
index 5869890b8fc7..bf085e95b28f 100644
--- a/drivers/gpu/drm/kmb/kmb_drv.h
+++ b/drivers/gpu/drm/kmb/kmb_drv.h
@@ -20,11 +20,18 @@
#define DRIVER_MAJOR 1
#define DRIVER_MINOR 1

+/* Platform definitions */
+#define KMB_CRTC_MIN_VFP 4
+#define KMB_CRTC_MAX_WIDTH 1920 /* max width in pixels */
+#define KMB_CRTC_MAX_HEIGHT 1080 /* max height in pixels */
+#define KMB_CRTC_MIN_WIDTH 1920
+#define KMB_CRTC_MIN_HEIGHT 1080
#define KMB_FB_MAX_WIDTH 1920
#define KMB_FB_MAX_HEIGHT 1080
#define KMB_FB_MIN_WIDTH 1
#define KMB_FB_MIN_HEIGHT 1
-
+#define KMB_MIN_VREFRESH 59 /*vertical refresh in Hz */
+#define KMB_MAX_VREFRESH 60 /*vertical refresh in Hz */
#define KMB_LCD_DEFAULT_CLK 200000000
#define KMB_SYS_CLK_MHZ 500

--
2.33.0