drm/tegra: dc: Select root window for event dispatch
In finish pageflip, the driver was not selecting the root window when
dispatching events. This exposed a race where a plane update would
change the window selection and cause tegra_dc_finish_page_flip to check
the wrong base address.
This patch also protects access to the window selection register as well
as the registers affected by it.
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index ef36f9d..978993f 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -168,7 +168,7 @@
const struct tegra_dc_window *window)
{
unsigned h_offset, v_offset, h_size, v_size, h_dda, v_dda, bpp;
- unsigned long value;
+ unsigned long value, flags;
bool yuv, planar;
/*
@@ -181,6 +181,8 @@
else
bpp = planar ? 1 : 2;
+ spin_lock_irqsave(&dc->lock, flags);
+
value = WINDOW_A_SELECT << index;
tegra_dc_writel(dc, value, DC_CMD_DISPLAY_WINDOW_HEADER);
@@ -273,6 +275,7 @@
case TEGRA_BO_TILING_MODE_BLOCK:
DRM_ERROR("hardware doesn't support block linear mode\n");
+ spin_unlock_irqrestore(&dc->lock, flags);
return -EINVAL;
}
@@ -331,6 +334,8 @@
tegra_dc_window_commit(dc, index);
+ spin_unlock_irqrestore(&dc->lock, flags);
+
return 0;
}
@@ -338,11 +343,14 @@
{
struct tegra_dc *dc = to_tegra_dc(plane->crtc);
struct tegra_plane *p = to_tegra_plane(plane);
+ unsigned long flags;
u32 value;
if (!plane->crtc)
return 0;
+ spin_lock_irqsave(&dc->lock, flags);
+
value = WINDOW_A_SELECT << p->index;
tegra_dc_writel(dc, value, DC_CMD_DISPLAY_WINDOW_HEADER);
@@ -352,6 +360,8 @@
tegra_dc_window_commit(dc, p->index);
+ spin_unlock_irqrestore(&dc->lock, flags);
+
return 0;
}
@@ -699,14 +709,16 @@
struct tegra_bo *bo = tegra_fb_get_plane(fb, 0);
unsigned int h_offset = 0, v_offset = 0;
struct tegra_bo_tiling tiling;
+ unsigned long value, flags;
unsigned int format, swap;
- unsigned long value;
int err;
err = tegra_fb_get_tiling(fb, &tiling);
if (err < 0)
return err;
+ spin_lock_irqsave(&dc->lock, flags);
+
tegra_dc_writel(dc, WINDOW_A_SELECT, DC_CMD_DISPLAY_WINDOW_HEADER);
value = fb->offsets[0] + y * fb->pitches[0] +
@@ -752,6 +764,7 @@
case TEGRA_BO_TILING_MODE_BLOCK:
DRM_ERROR("hardware doesn't support block linear mode\n");
+ spin_unlock_irqrestore(&dc->lock, flags);
return -EINVAL;
}
@@ -778,6 +791,8 @@
tegra_dc_writel(dc, value << 8, DC_CMD_STATE_CONTROL);
tegra_dc_writel(dc, value, DC_CMD_STATE_CONTROL);
+ spin_unlock_irqrestore(&dc->lock, flags);
+
return 0;
}
@@ -823,11 +838,16 @@
bo = tegra_fb_get_plane(crtc->primary->fb, 0);
+ spin_lock_irqsave(&dc->lock, flags);
+
/* check if new start address has been latched */
+ tegra_dc_writel(dc, WINDOW_A_SELECT, DC_CMD_DISPLAY_WINDOW_HEADER);
tegra_dc_writel(dc, READ_MUX, DC_CMD_STATE_ACCESS);
base = tegra_dc_readl(dc, DC_WINBUF_START_ADDR);
tegra_dc_writel(dc, 0, DC_CMD_STATE_ACCESS);
+ spin_unlock_irqrestore(&dc->lock, flags);
+
if (base == bo->paddr + crtc->primary->fb->offsets[0]) {
drm_crtc_send_vblank_event(crtc, dc->event);
drm_crtc_vblank_put(crtc);