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Commit b4155d7d authored by Sylwester Nawrocki's avatar Sylwester Nawrocki Committed by Mauro Carvalho Chehab
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[media] exynos4-is: Ensure fimc-is clocks are not enabled until properly configured 



Use clk_prepare_enable/clk_unprepare_disable instead of preparing the
clocks during the driver initalization and then using just clk_disable/
clk_enable. The clock framework doesn't guarantee a clock will not get
enabled during e.g. clk_set_parent if clk_prepare has been called on it.
So we ensure clk_prepare() is called only when it is safe to enable
the clocks, i.e. the parent clocks and the clocks' frequencies are set.
It must be ensured the FIMC-IS clocks have proper frequencies before they
are enabled, otherwise the whole system will hang.

Signed-off-by: default avatarSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: default avatarKyunmin Park <kyungmin.park@samsung.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 3cf138a6

drivers/media/platform/exynos4-is/fimc-is.c

+3 −10
Original line number Diff line number Diff line
@@ -71,7 +71,6 @@ static void fimc_is_put_clocks(struct fimc_is *is) 
	for (i = 0; i < ISS_CLKS_MAX; i++) {

		if (IS_ERR(is->clocks[i]))

			continue;

		clk_unprepare(is->clocks[i]);

		clk_put(is->clocks[i]);

		is->clocks[i] = ERR_PTR(-EINVAL);

	}
@@ -90,12 +89,6 @@ static int fimc_is_get_clocks(struct fimc_is *is) 
			ret = PTR_ERR(is->clocks[i]);

			goto err;

		}

		ret = clk_prepare(is->clocks[i]);

		if (ret < 0) {

			clk_put(is->clocks[i]);

			is->clocks[i] = ERR_PTR(-EINVAL);

			goto err;

		}

	}



	return 0;
@@ -103,7 +96,7 @@ static int fimc_is_get_clocks(struct fimc_is *is) 
	fimc_is_put_clocks(is);

	dev_err(&is->pdev->dev, "failed to get clock: %s\n",

		fimc_is_clocks[i]);

	return -ENXIO;

	return ret;

}



static int fimc_is_setup_clocks(struct fimc_is *is)
@@ -144,7 +137,7 @@ int fimc_is_enable_clocks(struct fimc_is *is) 
	for (i = 0; i < ISS_GATE_CLKS_MAX; i++) {

		if (IS_ERR(is->clocks[i]))

			continue;

		ret = clk_enable(is->clocks[i]);

		ret = clk_prepare_enable(is->clocks[i]);

		if (ret < 0) {

			dev_err(&is->pdev->dev, "clock %s enable failed\n",

				fimc_is_clocks[i]);
@@ -163,7 +156,7 @@ void fimc_is_disable_clocks(struct fimc_is *is) 


	for (i = 0; i < ISS_GATE_CLKS_MAX; i++) {

		if (!IS_ERR(is->clocks[i])) {

			clk_disable(is->clocks[i]);

			clk_disable_unprepare(is->clocks[i]);

			pr_debug("disabled clock: %s\n", fimc_is_clocks[i]);

		}

	}