Re: [PATCH v3 10/11] [ARM] tegra: Add framebuffer driver
flat view
From: Jaya Kumar <hidden>
Date: 2010-06-14 23:59:54
Also in:
linux-arm-kernel
On Tue, Jun 15, 2010 at 5:10 AM, Erik Gilling [off-list ref] wrote:
quoted hunk ↗ jump to hunk
diff --git a/drivers/video/tegrafb.c b/drivers/video/tegrafb.c new file mode 100644 index 0000000..47b2d42 --- /dev/null +++ b/drivers/video/tegrafb.c
+/* palette attary used by the fbcon */ +u32 pseudo_palette[16];
attary
quoted hunk ↗ jump to hunk
+ +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