On 29.06.2018 13:33, Krzysztof Kozlowski wrote:
> 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@xxxxxxxxxxxxxxx>
> Fixes: 5ee67b587a2b ("spi: dspi: clear SPI_SR before enable interrupt")
> Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
Reviewed-by: Stefan Agner <stefan@xxxxxxxx>
Up until commit d2233325e5b7 ("spi: spi-fsl-dspi: remove clk reference
when regmap_mmio initialize") regmap with clocks has been used. I guess
an alternative would have been to use this again, but I guess this has
been dropped for good reasons.
--
Stefan
> ---
> drivers/spi/spi-fsl-dspi.c | 24 ++++++++++++------------
> 1 file changed, 12 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
> index ff7456be9d6d..89a1e7a4fe5d 100644
> --- a/drivers/spi/spi-fsl-dspi.c
> +++ b/drivers/spi/spi-fsl-dspi.c
> @@ -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);
