linux-kernel - Re: [PATCH v10 5/5] usb: dwc3: core: cleanup IRQ resources

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Date:	Fri, 10 Jun 2016 14:44:55 +0300
From:	Sergei Shtylyov <sergei.shtylyov@...entembedded.com>
To:	Roger Quadros <rogerq@...com>, balbi@...nel.org,
	grygorii.strashko@...com
Cc:	tony@...mide.com, Joao.Pinto@...opsys.com,
	peter.chen@...escale.com, jun.li@...escale.com,
	yoshihiro.shimoda.uh@...esas.com, nsekhar@...com, b-liu@...com,
	linux-usb@...r.kernel.org, linux-omap@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v10 5/5] usb: dwc3: core: cleanup IRQ resources

On 6/10/2016 2:35 PM, Roger Quadros wrote:
> On 10/06/16 13:39, Sergei Shtylyov wrote:
>> Hello.
>>
>> On 6/10/2016 12:56 PM, Roger Quadros wrote:
>>
>>> Implementations might use different IRQs for
>>> host, gadget so use named interrupt resources
>>> to allow device tree to specify the interrupts.
>>>
>>> Following are the interrupt names
>>>
>>> Peripheral Interrupt - peripheral
>>> HOST Interrupt - host
>>>
>>> Maintain backward compatibility for a single named
>>> interrupt ("dwc3_usb3") for all interrupts as well as
>>> unnamed interrupt at index 0 for all interrupts.
>>>
>>> As platform_get_irq_() variants are used, tackle
>>
>>    platform_get_irq().
>
> OK.
>>
>>> the -EPROBE_DEFER case as well.
>>>
>>> Signed-off-by: Roger Quadros <rogerq@...com>
>>> ---
>>> v10:
>>> - don't mention otg irq since we are not using it yet
>>> - use platform_get_irq() and friends and check -EPROBE_DEFER case.
>>>
>>>  drivers/usb/dwc3/core.c   | 22 ++++++++--------------
>>>  drivers/usb/dwc3/gadget.c | 29 ++++++++++++++++++++++++++---
>>>  drivers/usb/dwc3/host.c   | 41 ++++++++++++++++++++++++++++++++++++++++-
>>>  3 files changed, 74 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
>>> index 8fceeb1..131e7eb 100644
>>> --- a/drivers/usb/dwc3/core.c
>>> +++ b/drivers/usb/dwc3/core.c
>> [...]
>>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
>>> index 0f6fb8e..774a0d8 100644
>>> --- a/drivers/usb/dwc3/gadget.c
>>> +++ b/drivers/usb/dwc3/gadget.c
>> [...]
>>> @@ -2866,7 +2865,31 @@ static irqreturn_t dwc3_interrupt(int irq, void *_evt)
>>>   */
>>>  int dwc3_gadget_init(struct dwc3 *dwc)
>>>  {
>>> -    int                    ret;
>>> +    int ret, irq;
>>> +    struct platform_device *dwc3_pdev = to_platform_device(dwc->dev);
>>> +
>>> +    irq = platform_get_irq_byname(dwc3_pdev, "peripheral");
>>> +    if (irq == -EPROBE_DEFER)
>>> +        return irq;
>>> +
>>> +    if (irq <= 0) {
>>> +        irq = platform_get_irq_byname(dwc3_pdev, "dwc_usb3");
>>> +        if (irq == -EPROBE_DEFER)
>>> +            return irq;
>>> +
>>> +        if (irq <= 0) {
>>> +            irq = platform_get_irq(dwc3_pdev, 0);
>>> +            if (irq <= 0) {
>>> +                if (irq != -EPROBE_DEFER) {
>>> +                    dev_err(dwc->dev,
>>> +                        "missing peripheral IRQ\n");
>>> +                }
>>> +                return irq;
>>
>>    Iff irq == 0, you'll return success despite IRQ was "invalid". Was that intended?
>
> good catch. It wasn't intended. I guess i'll return -EINVAL then?
>
>>
>>> +            }
>>> +        }
>>> +    }
>>> +
>>> +    dwc->irq_gadget = irq;
>>>
>>>      dwc->ctrl_req = dma_alloc_coherent(dwc->dev, sizeof(*dwc->ctrl_req),
>>>              &dwc->ctrl_req_addr, GFP_KERNEL);
>>> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
>>> index c679f63..eb5e8f9 100644
>>> --- a/drivers/usb/dwc3/host.c
>>> +++ b/drivers/usb/dwc3/host.c
>>> @@ -24,7 +24,46 @@ int dwc3_host_init(struct dwc3 *dwc)
>>>  {
>>>      struct platform_device    *xhci;
>>>      struct usb_xhci_pdata    pdata;
>>> -    int            ret;
>>> +    int            ret, irq;
>>> +    struct resource        *res;
>>> +    struct platform_device    *dwc3_pdev = to_platform_device(dwc->dev);
>>> +
>>> +    irq = platform_get_irq_byname(dwc3_pdev, "host");
>>> +    if (irq == -EPROBE_DEFER)
>>> +        return irq;
>>> +
>>> +    if (irq <= 0) {
>>> +        irq = platform_get_irq_byname(dwc3_pdev, "dwc_usb3");
>>> +        if (irq == -EPROBE_DEFER)
>>> +            return irq;
>>> +
>>> +        if (irq <= 0) {
>>> +            irq = platform_get_irq(dwc3_pdev, 0);
>>> +            if (irq <= 0) {
>>> +                if (irq != -EPROBE_DEFER) {
>>> +                    dev_err(dwc->dev,
>>> +                        "missing host IRQ\n");
>>> +                }
>>> +                return irq;
>>
>>    Iff irq == 0, you'll return success despite IRQ was "invalid". Was that intended?

    I'd just consider 0 a valid IRQ, that's simpler. FYI, I've submitted to 
Greg KH a patch fixing platform_get_irq[_byname]() to not return 0 on failure. 
No reaction so far...

> --
> cheers,
> -roger

MBR, Sergei