diff options
| -rw-r--r-- | drivers/gpu/drm/pl111/pl111_display.c | 36 | ||||
| -rw-r--r-- | drivers/gpu/drm/pl111/pl111_drm.h | 1 | ||||
| -rw-r--r-- | drivers/gpu/drm/pl111/pl111_drv.c | 6 |
3 files changed, 43 insertions, 0 deletions
diff --git a/drivers/gpu/drm/pl111/pl111_display.c b/drivers/gpu/drm/pl111/pl111_display.c index 5b8368c76734..310646427907 100644 --- a/drivers/gpu/drm/pl111/pl111_display.c +++ b/drivers/gpu/drm/pl111/pl111_display.c @@ -50,6 +50,41 @@ irqreturn_t pl111_irq(int irq, void *data) return status; } +static enum drm_mode_status +pl111_mode_valid(struct drm_crtc *crtc, + const struct drm_display_mode *mode) +{ + struct drm_device *drm = crtc->dev; + struct pl111_drm_dev_private *priv = drm->dev_private; + u32 cpp = priv->variant->fb_bpp / 8; + u64 bw; + + /* + * We use the pixelclock to also account for interlaced modes, the + * resulting bandwidth is in bytes per second. + */ + bw = mode->clock * 1000; /* In Hz */ + bw = bw * mode->hdisplay * mode->vdisplay * cpp; + bw = div_u64(bw, mode->htotal * mode->vtotal); + + /* + * If no bandwidth constraints, anything goes, else + * check if we are too fast. + */ + if (priv->memory_bw && (bw > priv->memory_bw)) { + DRM_DEBUG_KMS("%d x %d @ %d Hz, %d cpp, bw %llu too fast\n", + mode->hdisplay, mode->vdisplay, + mode->clock * 1000, cpp, bw); + + return MODE_BAD; + } + DRM_DEBUG_KMS("%d x %d @ %d Hz, %d cpp, bw %llu bytes/s OK\n", + mode->hdisplay, mode->vdisplay, + mode->clock * 1000, cpp, bw); + + return MODE_OK; +} + static int pl111_display_check(struct drm_simple_display_pipe *pipe, struct drm_plane_state *pstate, struct drm_crtc_state *cstate) @@ -348,6 +383,7 @@ static int pl111_display_prepare_fb(struct drm_simple_display_pipe *pipe, } static struct drm_simple_display_pipe_funcs pl111_display_funcs = { + .mode_valid = pl111_mode_valid, .check = pl111_display_check, .enable = pl111_display_enable, .disable = pl111_display_disable, diff --git a/drivers/gpu/drm/pl111/pl111_drm.h b/drivers/gpu/drm/pl111/pl111_drm.h index 2a93e0134061..8639b2d4ddf7 100644 --- a/drivers/gpu/drm/pl111/pl111_drm.h +++ b/drivers/gpu/drm/pl111/pl111_drm.h @@ -65,6 +65,7 @@ struct pl111_drm_dev_private { struct drm_simple_display_pipe pipe; void *regs; + u32 memory_bw; u32 ienb; u32 ctrl; /* The pixel clock (a reference to our clock divider off of CLCDCLK). */ diff --git a/drivers/gpu/drm/pl111/pl111_drv.c b/drivers/gpu/drm/pl111/pl111_drv.c index e92a406c9ea9..4621259d5387 100644 --- a/drivers/gpu/drm/pl111/pl111_drv.c +++ b/drivers/gpu/drm/pl111/pl111_drv.c @@ -257,6 +257,12 @@ static int pl111_amba_probe(struct amba_device *amba_dev, drm->dev_private = priv; priv->variant = variant; + if (of_property_read_u32(dev->of_node, "max-memory-bandwidth", + &priv->memory_bw)) { + dev_info(dev, "no max memory bandwidth specified, assume unlimited\n"); + priv->memory_bw = 0; + } + /* The two variants swap this register */ if (variant->is_pl110) { priv->ienb = CLCD_PL110_IENB; |