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

["Ardelean, Alexandru" <alexandru.Ardelean@xxxxxxxxxx>]

On Thu, 2020-04-09 at 17:23 +0200, Rafał 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: Rafał 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
>