On 07/22/2017 08:51 AM, Vinod Koul wrote:
> On Thu, Jul 06, 2017 at 02:20:20PM +0200, Pierre-Yves MORDRET wrote:
>> +static int stm32_dmamux_probe(struct platform_device *pdev)
>> +{
>> +    struct device_node *node = pdev->dev.of_node;
>> +    struct device_node *dma_node;
>> +    struct stm32_dmamux_data *stm32_dmamux;
>> +    struct resource *res;
>> +    void __iomem *iomem;
>> +    int i, ret;
>> +
>> +    if (!node)
>> +            return -ENODEV;
>> +
>> +    stm32_dmamux = devm_kzalloc(&pdev->dev, sizeof(*stm32_dmamux),
>> +                                GFP_KERNEL);
>> +    if (!stm32_dmamux)
>> +            return -ENOMEM;
>> +
>> +    dma_node = of_parse_phandle(node, "dma-masters", 0);
>> +    if (!dma_node) {
>> +            dev_err(&pdev->dev, "Can't get DMA master node\n");
>> +            return -ENODEV;
>> +    }
>> +
>> +    if (device_property_read_u32(&pdev->dev, "dma-channels",
>> +                                 &stm32_dmamux->dmamux_channels))
>> +            stm32_dmamux->dmamux_channels = STM32_DMAMUX_MAX_CHANNELS;
>> +
>> +    if (device_property_read_u32(&pdev->dev, "dma-requests",
>> +                                 &stm32_dmamux->dmamux_requests))
>> +            stm32_dmamux->dmamux_requests = STM32_DMAMUX_MAX_REQUESTS;
> 
> I think defaults should be warned here too
> 

ok

>> +
>> +    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +    if (!res)
>> +            return -ENODEV;
>> +
>> +    iomem = devm_ioremap_resource(&pdev->dev, res);
>> +    if (!iomem)
>> +            return -ENOMEM;
>> +
>> +    spin_lock_init(&stm32_dmamux->lock);
>> +
>> +    stm32_dmamux->clk = devm_clk_get(&pdev->dev, NULL);
>> +    if (IS_ERR(stm32_dmamux->clk)) {
>> +            dev_info(&pdev->dev, "Missing controller clock\n");
> 
> Can you check for EPROBE_DEFER and print only for if that is not the error
> otherwise we end up sapmming with defered probe issues
> 

This is what you meant ?
        if (IS_ERR(stm32_dmamux->clk) != EPROBE_DEFER) {
                dev_info(&pdev->dev, "Missing controller clock\n");
                return PTR_ERR(stm32_dmamux->clk);
        }

OR

        if (IS_ERR(stm32_dmamux->clk)) {
                if (IS_ERR(stm32_dmamux->clk) != EPROBE_DEFER)
                        dev_info(&pdev->dev, "Missing controller clock\n");
                return PTR_ERR(stm32_dmamux->clk);
        }

>> +
>> +#ifndef __DMA_STM32_DMAMUX_H
>> +#define __DMA_STM32_DMAMUX_H
>> +
>> +#if defined(CONFIG_STM32_DMAMUX)
>> +int stm32_dmamux_set_config(struct device *dev, void *route_data, u32 
>> chan_id);
> 
> Why do we need a custom API in this case?
> 

This API is called by DMA when a slave is requested by client. DMA can work
without DMAMUX this API has been put in place to configure DMAMUX whether client
is requesting a DMAMUX Channel instead of a DMA one.

Thanks
Py

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