memory: tegra30-emc: Firm up suspend/resume sequence (51bb73f9) · Commits · 戴 / test

drivers/memory/tegra/tegra30-emc.c

+20 −18

Original line number	Diff line number	Diff line
		@@ -346,7 +346,6 @@ struct tegra_emc {
		bool vref_cal_toggle : 1;
		bool zcal_long : 1;
		bool dll_on : 1;
		bool prepared : 1;
		bool bad_state : 1;

		struct {
		@@ -758,9 +757,6 @@ static int emc_prepare_timing_change(struct tegra_emc *emc, unsigned long rate)
		/* interrupt can be re-enabled now */
		enable_irq(emc->irq);

		emc->bad_state = false;
		emc->prepared = true;

		return 0;
		}

		@@ -769,13 +765,12 @@ static int emc_complete_timing_change(struct tegra_emc *emc,
		{
		struct emc_timing *timing = emc_find_timing(emc, rate);
		unsigned long timeout;
		int ret;
		int err;

		timeout = wait_for_completion_timeout(&emc->clk_handshake_complete,
		msecs_to_jiffies(100));
		if (timeout == 0) {
		dev_err(emc->dev, "emc-car handshake failed\n");
		emc->bad_state = true;
		return -EIO;
		}

		@@ -797,22 +792,23 @@ static int emc_complete_timing_change(struct tegra_emc *emc,

		udelay(2);
		/* update restored timing */
		ret = emc_seq_update_timing(emc);
		if (ret)
		emc->bad_state = true;
		err = emc_seq_update_timing(emc);

		/* restore early ACK */
		mc_writel(emc->mc, emc->mc_override, MC_EMEM_ARB_OVERRIDE);

		emc->prepared = false;
		if (err)
		return err;

		emc->bad_state = false;

		return ret;
		return 0;
		}

		static int emc_unprepare_timing_change(struct tegra_emc *emc,
		unsigned long rate)
		{
		if (emc->prepared && !emc->bad_state) {
		if (!emc->bad_state) {
		/* shouldn't ever happen in practice */
		dev_err(emc->dev, "timing configuration can't be reverted\n");
		emc->bad_state = true;
		@@ -1354,13 +1350,17 @@ unset_cb:
		static int tegra_emc_suspend(struct device *dev)
		{
		struct tegra_emc *emc = dev_get_drvdata(dev);
		int err;

		/*
		* Suspending in a bad state will hang machine. The "prepared" var
		* shall be always false here unless it's a kernel bug that caused
		* suspending in a wrong order.
		*/
		if (WARN_ON(emc->prepared) \|\| emc->bad_state)
		/* take exclusive control over the clock's rate */
		err = clk_rate_exclusive_get(emc->clk);
		if (err) {
		dev_err(emc->dev, "failed to acquire clk: %d\n", err);
		return err;
		}

		/* suspending in a bad state will hang machine */
		if (WARN(emc->bad_state, "hardware in a bad state\n"))
		return -EINVAL;

		emc->bad_state = true;
		@@ -1375,6 +1375,8 @@ static int tegra_emc_resume(struct device *dev)
		emc_setup_hw(emc);
		emc->bad_state = false;

		clk_rate_exclusive_put(emc->clk);

		return 0;
		}

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