i2c: tegra: Better handle case where CPU0 is busy for a long time (a900aeac) · Commits · 戴 / test

drivers/i2c/busses/i2c-tegra.c

+15 −12

Original line number	Diff line number	Diff line
		@@ -996,7 +996,7 @@ tegra_i2c_poll_completion_timeout(struct tegra_i2c_dev *i2c_dev,
		do {
		u32 status = i2c_readl(i2c_dev, I2C_INT_STATUS);

		if (status) {
		if (status)
		tegra_i2c_isr(i2c_dev->irq, i2c_dev);

		if (completion_done(complete)) {
		@@ -1004,7 +1004,6 @@ tegra_i2c_poll_completion_timeout(struct tegra_i2c_dev *i2c_dev,

		return msecs_to_jiffies(delta) ?: 1;
		}
		}

		ktime = ktime_get();

		@@ -1030,14 +1029,18 @@ tegra_i2c_wait_completion_timeout(struct tegra_i2c_dev *i2c_dev,
		disable_irq(i2c_dev->irq);

		/*
		* There is a chance that completion may happen after IRQ
		* synchronization, which is done by disable_irq().
		* Under some rare circumstances (like running KASAN +
		* NFS root) CPU, which handles interrupt, may stuck in
		* uninterruptible state for a significant time. In this
		* case we will get timeout if I2C transfer is running on
		* a sibling CPU, despite of IRQ being raised.
		*
		* In order to handle this rare condition, the IRQ status
		* needs to be checked after timeout.
		*/
		if (ret == 0 && completion_done(complete)) {
		dev_warn(i2c_dev->dev,
		"completion done after timeout\n");
		ret = 1;
		}
		if (ret == 0)
		ret = tegra_i2c_poll_completion_timeout(i2c_dev,
		complete, 0);
		}

		return ret;