On Tue, Jun 15, 2010 at 5:10 AM, Erik Gilling [off-list ref] wrote:

+/* palette attary used by the fbcon */
+u32 pseudo_palette[16];

attary

+
+irqreturn_t tegra_fb_irq(int irq, void *ptr)
+{
+ ? ? ? struct fb_info *info = ptr;
+ ? ? ? struct tegra_fb_info *tegra_fb = info->par;
+
+ ? ? ? u32 reg = tegra_fb_readl(tegra_fb, DC_CMD_INT_STATUS);
+ ? ? ? tegra_fb_writel(tegra_fb, reg, DC_CMD_INT_STATUS);
+
+ ? ? ? tegra_fb->wait_condition = 1;
+ ? ? ? wake_up(&tegra_fb->event_wq);
+ ? ? ? return IRQ_HANDLED;
+}
+
+static int tegra_fb_wait_for_event(struct tegra_fb_info *tegra_fb,
+ ? ? ? unsigned long timeout, u32 irq_mask)
+{
+ ? ? ? u32 reg;
+
+ ? ? ? tegra_fb->wait_condition = 0;
+
+ ? ? ? reg = tegra_fb_readl(tegra_fb, DC_CMD_INT_MASK);
+ ? ? ? reg |= irq_mask;
+ ? ? ? tegra_fb_writel(tegra_fb, reg, DC_CMD_INT_MASK);
+
+ ? ? ? /* Clear any pending interrupt */
+ ? ? ? tegra_fb_writel(tegra_fb, irq_mask, DC_CMD_INT_STATUS);
+
+ ? ? ? tegra_fb_writel(tegra_fb, irq_mask, DC_CMD_INT_ENABLE);
+
+ ? ? ? /* Wait for the irq to fire */
+ ? ? ? wait_event_interruptible_timeout(tegra_fb->event_wq,
+ ? ? ? ? ? ? ? tegra_fb->wait_condition, timeout);
+
+ ? ? ? tegra_fb_writel(tegra_fb, 0, DC_CMD_INT_ENABLE);
+
+ ? ? ? if (!tegra_fb->wait_condition) {
+ ? ? ? ? ? ? ? pr_warning("%s: wait for vsync timed out\n", __func__);
+ ? ? ? ? ? ? ? return -ETIMEDOUT;
+ ? ? ? }
+ ? ? ? return 0;
+}

Apologies for the incremental review. The wait_condition code above
looks odd to me. Typically, we just test the return value of
wait_event_interruptible_timeout to see whether it timed out (returns
0 if so). But I guess the above approach works as well.

+               if (tegra_fb_wait_for_event(tegra_fb, HZ/10, DC_INT_FRAME_END))

I still didn't follow how tegra_fb_activate is using the -ETIMEDOUT
return value from the wait, it seems like it is just ignored. You are
also doing stuff like HZ/10 and you might prefer to use
msecs_to_jiffies.

Thanks,
jaya