linux-kernel - Re: [PATCH v10 01/11] drm/etnaviv: Add a dedicated function to register an irq handler

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Message-ID: <7659b79a-7e13-3be8-0be7-0b8d250206d8@loongson.cn>
Date:   Wed, 21 Jun 2023 17:34:14 +0800
From:   Sui Jingfeng <suijingfeng@...ngson.cn>
To:     Lucas Stach <l.stach@...gutronix.de>,
        Sui Jingfeng <18949883232@....com>,
        Russell King <linux+etnaviv@...linux.org.uk>,
        Christian Gmeiner <christian.gmeiner@...il.com>,
        David Airlie <airlied@...il.com>,
        Daniel Vetter <daniel@...ll.ch>
Cc:     linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        etnaviv@...ts.freedesktop.org,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Bjorn Helgaas <bhelgaas@...gle.com>
Subject: Re: [PATCH v10 01/11] drm/etnaviv: Add a dedicated function to
 register an irq handler

Hi,

On 2023/6/21 17:07, Lucas Stach wrote:
> Am Dienstag, dem 20.06.2023 um 17:47 +0800 schrieb Sui Jingfeng:
>> From: Sui Jingfeng <suijingfeng@...ngson.cn>
>>
>> Because getting IRQ from a device is platform-dependent, PCI devices have
>> different methods for getting an IRQ. This patch is a preparation to extend
>> this driver for supporting the PCI devices.
>>
>> Cc: Lucas Stach <l.stach@...gutronix.de>
>> Cc: Christian Gmeiner <christian.gmeiner@...il.com>
>> Cc: Philipp Zabel <p.zabel@...gutronix.de>
>> Cc: Bjorn Helgaas <bhelgaas@...gle.com>
>> Cc: Daniel Vetter <daniel@...ll.ch>
>> Signed-off-by: Sui Jingfeng <suijingfeng@...ngson.cn>
>> ---
>>   drivers/gpu/drm/etnaviv/etnaviv_gpu.c | 32 +++++++++++++++++++--------
>>   1 file changed, 23 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
>> index de8c9894967c..a03e81337d8f 100644
>> --- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
>> +++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
>> @@ -1817,6 +1817,27 @@ static const struct of_device_id etnaviv_gpu_match[] = {
>>   };
>>   MODULE_DEVICE_TABLE(of, etnaviv_gpu_match);
>>   
>> +static int etnaviv_gpu_register_irq(struct etnaviv_gpu *gpu, int irq)
>> +{
>> +	struct device *dev = gpu->dev;
>> +	int err;
>> +
>> +	if (irq < 0)
>> +		return irq;
>> +
>> +	err = devm_request_irq(dev, irq, irq_handler, 0, dev_name(dev), gpu);
>> +	if (err) {
>> +		dev_err(dev, "failed to request irq %u: %d\n", irq, err);
>> +		return err;
>> +	}
>> +
>> +	gpu->irq = irq;
>> +
>> +	dev_info(dev, "irq(%d) handler registered\n", irq);
> There is no reason to put this into the kernel log. It's no different
> than other resources to the driver and we don't log each one of those
> either.
>
> In fact I don't see any reason for this change in the first place.
> Effectively you are moving a single function call into a new function,
> which doesn't seem like an improvement.

Hi, another reason is that we observed that

It(register irq) has no relationship to rest of the 
etnaviv_gpu_driver_create() funciton,

so it should be stand alone.

After stand alone, it is not platform-dependent any more,

it can be shared by both the PCI device driver and the platform device 
driver.


So, this is what I'm thinking when I create this function.

> Regards,
> Lucas
>
>> +
>> +	return 0;
>> +}
>> +
>>   static int etnaviv_gpu_platform_probe(struct platform_device *pdev)
>>   {
>>   	struct device *dev = &pdev->dev;
>> @@ -1837,16 +1858,9 @@ static int etnaviv_gpu_platform_probe(struct platform_device *pdev)
>>   		return PTR_ERR(gpu->mmio);
>>   
>>   	/* Get Interrupt: */
>> -	gpu->irq = platform_get_irq(pdev, 0);
>> -	if (gpu->irq < 0)
>> -		return gpu->irq;
>> -
>> -	err = devm_request_irq(&pdev->dev, gpu->irq, irq_handler, 0,
>> -			       dev_name(gpu->dev), gpu);
>> -	if (err) {
>> -		dev_err(dev, "failed to request IRQ%u: %d\n", gpu->irq, err);
>> +	err = etnaviv_gpu_register_irq(gpu, platform_get_irq(pdev, 0));
>> +	if (err)
>>   		return err;
>> -	}
>>   
>>   	/* Get Clocks: */
>>   	gpu->clk_reg = devm_clk_get_optional(&pdev->dev, "reg");

-- 
Jingfeng