Re: [PATCH] spi: spi-axi-spi-engine: Access register after clock initialization

From: Ardelean, Alexandru
Date: Thu Apr 09 2020 - 11:26:50 EST



On Thu, 2020-04-09 at 17:23 +0200, RafaÅ Hibner wrote:
> [External]
>
> Move register access after clock initialization.
>
> Clock "s_axi_aclk" is needed for register access. Without the clock running
>
> AXI bus hangs and causes kernel freeze.
>

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Out of curiosity: did you use the 'git send-email' command for this patch?


> Cc: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>
>
> Signed-off-by: RafaÅ Hibner <rafal.hibner@xxxxxxxxxxxx>
>
> ---
>
> drivers/spi/spi-axi-spi-engine.c | 32 ++++++++++++++++----------------
>
> 1 file changed, 16 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-
> engine.c
>
> index eb9b78a90d..af86e6d6e1 100644
>
> --- a/drivers/spi/spi-axi-spi-engine.c
>
> +++ b/drivers/spi/spi-axi-spi-engine.c
>
> @@ -489,22 +489,6 @@ static int spi_engine_probe(struct platform_device *pdev)
>
>
>
> spin_lock_init(&spi_engine->lock);
>
>
>
> - spi_engine->base = devm_platform_ioremap_resource(pdev, 0);
>
> - if (IS_ERR(spi_engine->base)) {
>
> - ret = PTR_ERR(spi_engine->base);
>
> - goto err_put_master;
>
> - }
>
> -
>
> - version = readl(spi_engine->base + SPI_ENGINE_REG_VERSION);
>
> - if (SPI_ENGINE_VERSION_MAJOR(version) != 1) {
>
> - dev_err(&pdev->dev, "Unsupported peripheral version %u.%u.%c\n",
>
> - SPI_ENGINE_VERSION_MAJOR(version),
>
> - SPI_ENGINE_VERSION_MINOR(version),
>
> - SPI_ENGINE_VERSION_PATCH(version));
>
> - ret = -ENODEV;
>
> - goto err_put_master;
>
> - }
>
> -
>
> spi_engine->clk = devm_clk_get(&pdev->dev, "s_axi_aclk");
>
> if (IS_ERR(spi_engine->clk)) {
>
> ret = PTR_ERR(spi_engine->clk);
>
> @@ -525,6 +509,22 @@ static int spi_engine_probe(struct platform_device *pdev)
>
> if (ret)
>
> goto err_clk_disable;
>
>
>
> + spi_engine->base = devm_platform_ioremap_resource(pdev, 0);
>
> + if (IS_ERR(spi_engine->base)) {
>
> + ret = PTR_ERR(spi_engine->base);
>
> + goto err_ref_clk_disable;
>
> + }
>
> +
>
> + version = readl(spi_engine->base + SPI_ENGINE_REG_VERSION);
>
> + if (SPI_ENGINE_VERSION_MAJOR(version) != 1) {
>
> + dev_err(&pdev->dev, "Unsupported peripheral version %u.%u.%c\n",
>
> + SPI_ENGINE_VERSION_MAJOR(version),
>
> + SPI_ENGINE_VERSION_MINOR(version),
>
> + SPI_ENGINE_VERSION_PATCH(version));
>
> + ret = -ENODEV;
>
> + goto err_ref_clk_disable;
>
> + }
>
> +
>
> writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_RESET);
>
> writel_relaxed(0xff, spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
>
> writel_relaxed(0x00, spi_engine->base + SPI_ENGINE_REG_INT_ENABLE);
>
> --
>
> 2.24.1
>