Unverified Commit d8ffee2f authored Jun 29, 2018 by Krzysztof Kozlowski Committed by Mark Brown Jul 02, 2018

spi: spi-fsl-dspi: Fix imprecise abort on VF500 during probe



Registers of DSPI should not be accessed before enabling its clock.  On
Toradex Colibri VF50 on Iris carrier board this could be seen during
bootup as imprecise abort:

    Unhandled fault: imprecise external abort (0x1c06) at 0x00000000
    Internal error: : 1c06 [#1] ARM
    Modules linked in:
    CPU: 0 PID: 1 Comm: swapper Not tainted 4.14.39-dirty #97
    Hardware name: Freescale Vybrid VF5xx/VF6xx (Device Tree)
    Backtrace:
    [<804166a8>] (regmap_write) from [<80466b5c>] (dspi_probe+0x1f0/0x8dc)
    [<8046696c>] (dspi_probe) from [<8040107c>] (platform_drv_probe+0x54/0xb8)
    [<80401028>] (platform_drv_probe) from [<803ff53c>] (driver_probe_device+0x280/0x2f8)
    [<803ff2bc>] (driver_probe_device) from [<803ff674>] (__driver_attach+0xc0/0xc4)
    [<803ff5b4>] (__driver_attach) from [<803fd818>] (bus_for_each_dev+0x70/0xa4)
    [<803fd7a8>] (bus_for_each_dev) from [<803fee74>] (driver_attach+0x24/0x28)
    [<803fee50>] (driver_attach) from [<803fe980>] (bus_add_driver+0x1a0/0x218)
    [<803fe7e0>] (bus_add_driver) from [<803fffe8>] (driver_register+0x80/0x100)
    [<803fff68>] (driver_register) from [<80400fdc>] (__platform_driver_register+0x48/0x50)
    [<80400f94>] (__platform_driver_register) from [<8091cf7c>] (fsl_dspi_driver_init+0x1c/0x20)
    [<8091cf60>] (fsl_dspi_driver_init) from [<8010195c>] (do_one_initcall+0x4c/0x174)
    [<80101910>] (do_one_initcall) from [<80900e8c>] (kernel_init_freeable+0x144/0x1d8)
    [<80900d48>] (kernel_init_freeable) from [<805ff6a8>] (kernel_init+0x10/0x114)
    [<805ff698>] (kernel_init) from [<80107be8>] (ret_from_fork+0x14/0x2c)

Cc: <stable@vger.kernel.org>
Fixes: 5ee67b58 ("spi: dspi: clear SPI_SR before enable interrupt")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

parent 22d71a50

drivers/spi/spi-fsl-dspi.c

+12 −12

Original line number	Diff line number	Diff line
		@@ -1071,30 +1071,30 @@ static int dspi_probe(struct platform_device *pdev)
		}
		}

		dspi->clk = devm_clk_get(&pdev->dev, "dspi");
		if (IS_ERR(dspi->clk)) {
		ret = PTR_ERR(dspi->clk);
		dev_err(&pdev->dev, "unable to get clock\n");
		goto out_master_put;
		}
		ret = clk_prepare_enable(dspi->clk);
		if (ret)
		goto out_master_put;

		dspi_init(dspi);
		dspi->irq = platform_get_irq(pdev, 0);
		if (dspi->irq < 0) {
		dev_err(&pdev->dev, "can't get platform irq\n");
		ret = dspi->irq;
		goto out_master_put;
		goto out_clk_put;
		}

		ret = devm_request_irq(&pdev->dev, dspi->irq, dspi_interrupt, 0,
		pdev->name, dspi);
		if (ret < 0) {
		dev_err(&pdev->dev, "Unable to attach DSPI interrupt\n");
		goto out_master_put;
		}

		dspi->clk = devm_clk_get(&pdev->dev, "dspi");
		if (IS_ERR(dspi->clk)) {
		ret = PTR_ERR(dspi->clk);
		dev_err(&pdev->dev, "unable to get clock\n");
		goto out_master_put;
		goto out_clk_put;
		}
		ret = clk_prepare_enable(dspi->clk);
		if (ret)
		goto out_master_put;

		if (dspi->devtype_data->trans_mode == DSPI_DMA_MODE) {
		ret = dspi_request_dma(dspi, res->start);