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Commit 42977334 authored by Marcel Ziswiler's avatar Marcel Ziswiler Committed by Greg Kroah-Hartman
Browse files

spi: tegra20-slink: explicitly enable/disable clock 



commit 7001cab1dabc0b72b2b672ef58a90ab64f5e2343 upstream.

Depending on the SPI instance one may get an interrupt storm upon
requesting resp. interrupt unless the clock is explicitly enabled
beforehand. This has been observed trying to bring up instance 4 on
T20.

Signed-off-by: default avatarMarcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent dc89d37f

drivers/spi/spi-tegra20-slink.c

+23 −8
Original line number Diff line number Diff line
@@ -1063,6 +1063,24 @@ static int tegra_slink_probe(struct platform_device *pdev) 
		goto exit_free_master;

	}



	/* disabled clock may cause interrupt storm upon request */

	tspi->clk = devm_clk_get(&pdev->dev, NULL);

	if (IS_ERR(tspi->clk)) {

		ret = PTR_ERR(tspi->clk);

		dev_err(&pdev->dev, "Can not get clock %d\n", ret);

		goto exit_free_master;

	}

	ret = clk_prepare(tspi->clk);

	if (ret < 0) {

		dev_err(&pdev->dev, "Clock prepare failed %d\n", ret);

		goto exit_free_master;

	}

	ret = clk_enable(tspi->clk);

	if (ret < 0) {

		dev_err(&pdev->dev, "Clock enable failed %d\n", ret);

		goto exit_free_master;

	}



	spi_irq = platform_get_irq(pdev, 0);

	tspi->irq = spi_irq;

	ret = request_threaded_irq(tspi->irq, tegra_slink_isr,
@@ -1071,14 +1089,7 @@ static int tegra_slink_probe(struct platform_device *pdev) 
	if (ret < 0) {

		dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n",

					tspi->irq);

		goto exit_free_master;

	}



	tspi->clk = devm_clk_get(&pdev->dev, NULL);

	if (IS_ERR(tspi->clk)) {

		dev_err(&pdev->dev, "can not get clock\n");

		ret = PTR_ERR(tspi->clk);

		goto exit_free_irq;

		goto exit_clk_disable;

	}



	tspi->rst = devm_reset_control_get_exclusive(&pdev->dev, "spi");
@@ -1138,6 +1149,8 @@ static int tegra_slink_probe(struct platform_device *pdev) 
	tegra_slink_deinit_dma_param(tspi, true);

exit_free_irq:

	free_irq(spi_irq, tspi);

exit_clk_disable:

	clk_disable(tspi->clk);

exit_free_master:

	spi_master_put(master);

	return ret;
@@ -1150,6 +1163,8 @@ static int tegra_slink_remove(struct platform_device *pdev) 


	free_irq(tspi->irq, tspi);



	clk_disable(tspi->clk);



	if (tspi->tx_dma_chan)

		tegra_slink_deinit_dma_param(tspi, false);