Re: [PATCH v2] dmaengine: axi-dmac: Request IRQ with IRQF_SHARED

From: Lars-Peter Clausen
Date: Fri Apr 27 2018 - 02:54:00 EST


On 04/27/2018 07:11 AM, Vinod Koul wrote:
> On Thu, Apr 26, 2018 at 10:40:00AM -0700, Moritz Fischer wrote:
>> Request IRQ with IRQF_SHARED flag. This works since the interrupt
>> handler already checks if there is an actual IRQ pending and returns
>> IRQ_NONE otherwise.
>
> hmmm what are we trying to fix here? Is your device on a shared line or not?

IRQF_SHARED does not mean that the IRQ is on a shared line. It means that
the driver can handle it if the IRQ is on a shared line. Since the driver
can handle it setting the flag is a good idea since this enables usecases
where the line is shared.

>
>>
>> Acked-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
>> Signed-off-by: Moritz Fischer <mdf@xxxxxxxxxx>
>> ---
>> Changes from v1:
>> - Added Lars' Acked-by
>> - Dropped patch [1/2] and changed accordingly
>> ---
>> drivers/dma/dma-axi-dmac.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/dma/dma-axi-dmac.c b/drivers/dma/dma-axi-dmac.c
>> index 2419fe524daa..15b2453d2647 100644
>> --- a/drivers/dma/dma-axi-dmac.c
>> +++ b/drivers/dma/dma-axi-dmac.c
>> @@ -687,7 +687,7 @@ static int axi_dmac_probe(struct platform_device *pdev)
>> if (ret)
>> goto err_unregister_device;
>>
>> - ret = request_irq(dmac->irq, axi_dmac_interrupt_handler, 0,
>> + ret = request_irq(dmac->irq, axi_dmac_interrupt_handler, IRQF_SHARED,
>> dev_name(&pdev->dev), dmac);
>> if (ret)
>> goto err_unregister_of;
>> --
>> 2.17.0
>>
>